diff --git a/scenarios/grpc.js b/scenarios/grpc.js
index 548b1c6..9c8d0df 100644
--- a/scenarios/grpc.js
+++ b/scenarios/grpc.js
@@ -99,8 +99,8 @@ export function teardown(data) {
 }
 
 export function obj_write() {
-    if (__ENV.SLEEP) {
-        sleep(__ENV.SLEEP);
+    if (__ENV.SLEEP_WRITE) {
+        sleep(__ENV.SLEEP_WRITE);
     }
 
     const headers = {
@@ -121,8 +121,8 @@ export function obj_write() {
 }
 
 export function obj_read() {
-    if (__ENV.SLEEP) {
-        sleep(__ENV.SLEEP);
+    if (__ENV.SLEEP_READ) {
+        sleep(__ENV.SLEEP_READ);
     }
 
     const obj = obj_list[Math.floor(Math.random() * obj_list.length)];
@@ -133,8 +133,8 @@ export function obj_read() {
 }
 
 export function obj_delete() {
-    if (__ENV.SLEEP) {
-        sleep(__ENV.SLEEP);
+    if (__ENV.SLEEP_DELETE) {
+        sleep(__ENV.SLEEP_DELETE);
     }
 
     const obj = obj_to_delete_selector.nextObject();
diff --git a/scenarios/http.js b/scenarios/http.js
index 558aaa3..b48df70 100644
--- a/scenarios/http.js
+++ b/scenarios/http.js
@@ -72,8 +72,8 @@ export function teardown(data) {
 }
 
 export function obj_write() {
-    if (__ENV.SLEEP) {
-        sleep(__ENV.SLEEP);
+    if (__ENV.SLEEP_WRITE) {
+        sleep(__ENV.SLEEP_WRITE);
     }
 
     const container = container_list[Math.floor(Math.random() * container_list.length)];
@@ -96,8 +96,8 @@ export function obj_write() {
 }
 
 export function obj_read() {
-    if (__ENV.SLEEP) {
-        sleep(__ENV.SLEEP);
+    if (__ENV.SLEEP_READ) {
+        sleep(__ENV.SLEEP_READ);
     }
 
     const obj = obj_list[Math.floor(Math.random() * obj_list.length)];
diff --git a/scenarios/preset/preset_grpc.py b/scenarios/preset/preset_grpc.py
index bc3f119..8dc2b63 100755
--- a/scenarios/preset/preset_grpc.py
+++ b/scenarios/preset/preset_grpc.py
@@ -1,25 +1,26 @@
 #!/usr/bin/python3
 
-from multiprocessing import Process
-import uuid
-import shlex
-from subprocess import check_output, CalledProcessError, STDOUT
+import argparse
 import json
-import os 
-import argparse, sys
-
+import os
+import shlex
 from concurrent.futures import ProcessPoolExecutor
+from subprocess import check_output, CalledProcessError, STDOUT
 
-parser=argparse.ArgumentParser()
-
+parser = argparse.ArgumentParser()
 parser.add_argument('--size', help='Upload objects size in kb')
 parser.add_argument('--containers', help='Number of containers to create')
 parser.add_argument('--out', help='JSON file with output')
 parser.add_argument('--preload_obj', help='Number of pre-loaded objects')
+parser.add_argument(
+    "--policy",
+    help="Container placement policy",
+    default="REP 1 IN X CBF 1 SELECT 1 FROM * AS X"
+)
 parser.add_argument('--endpoint', help='Node address')
 parser.add_argument('--update', help='Save existed containers')
 
-args=parser.parse_args()
+args = parser.parse_args()
 print(args)
 
 
@@ -33,7 +34,6 @@ def main():
         with open(args.out) as f:
             data_json = json.load(f)
             container_list = data_json['containers']
-        # Get CID list
     else:
         print(f"Create containers: {args.containers}")
         with ProcessPoolExecutor(max_workers=10) as executor:
@@ -78,6 +78,7 @@ def random_payload(payload_filepath):
     with open('%s'%payload_filepath, 'wb') as fout:
         fout.write(os.urandom(1024*int(args.size))) 
 
+
 def execute_cmd(cmd_line):
     args = shlex.split(cmd_line)
     output = ""
@@ -93,11 +94,11 @@ def execute_cmd(cmd_line):
 
 
 def create_container():
-    cmd_line = f"neofs-cli --rpc-endpoint {args.endpoint} container create -g --policy 'REP 1 IN X CBF 1 SELECT 1 FROM * AS X' --basic-acl public-read-write --await"   
+    cmd_line = f"neofs-cli --rpc-endpoint {args.endpoint} container create -g --policy {args.policy} --basic-acl public-read-write --await"
     output, success = execute_cmd(cmd_line)
 
     if not success:
-            print(f" > Container has not been created.")
+        print(f" > Container has not been created.")
     else:
         try:
             fst_str = output.split('\n')[0]
diff --git a/scenarios/run_scenarios.md b/scenarios/run_scenarios.md
index 5a082ee..62dabb1 100644
--- a/scenarios/run_scenarios.md
+++ b/scenarios/run_scenarios.md
@@ -11,7 +11,8 @@ Scenarios `grpc.js`, `http.js` and `s3.js` support the following options:
   * `REGISTRY_FILE` - if set, all produced objects will be stored in database for subsequent verification. Database file name will be set to the value of `REGISTRY_FILE`.
   * `WRITE_OBJ_SIZE` - object size in kb for write(PUT) operations.
   * `PREGEN_JSON` - path to json file with pre-generated containers and objects (in case of http scenario we use json pre-generated for grpc scenario).
-  * `SLEEP` - time interval (in seconds) between VU iterations.
+  * `SLEEP_WRITE` - time interval (in seconds) between writing VU iterations.
+  * `SLEEP_READ` - time interval (in seconds) between reading VU iterations.
 
 Examples of how to use these options are provided below for each scenario.
 
@@ -35,6 +36,7 @@ Options (in addition to the common options):
   * `GRPC_ENDPOINTS` - GRPC endpoints of neoFS in format `host:port`. To specify multiple endpoints separate them by comma.
   * `DELETERS` - number of VUs performing delete operations (using deleters requires that options `DELETE_AGE` and `REGISTRY_FILE` are specified as well).
   * `DELETE_AGE` - age of object in seconds before which it can not be deleted. This parameter can be used to control how many objects we have in the system under load.
+  * `SLEEP_DELETE` - time interval (in seconds) between deleting VU iterations.
 
 ## HTTP
 
@@ -90,6 +92,7 @@ Options (in addition to the common options):
   * `S3_ENDPOINTS` - endpoints of S3 gateways in format `host:port`. To specify multiple endpoints separate them by comma.
   * `DELETERS` - number of VUs performing delete operations (using deleters requires that options `DELETE_AGE` and `REGISTRY_FILE` are specified as well).
   * `DELETE_AGE` - age of object in seconds before which it can not be deleted. This parameter can be used to control how many objects we have in the system under load.
+  * `SLEEP_DELETE` - time interval (in seconds) between deleting VU iterations.
   * `OBJ_NAME` - if specified, this name will be used for all write operations instead of random generation.
 
 ## Verify
diff --git a/scenarios/s3.js b/scenarios/s3.js
index e28b536..cc8d294 100644
--- a/scenarios/s3.js
+++ b/scenarios/s3.js
@@ -98,8 +98,8 @@ export function teardown(data) {
 }
 
 export function obj_write() {
-    if (__ENV.SLEEP) {
-        sleep(__ENV.SLEEP);
+    if (__ENV.SLEEP_WRITE) {
+        sleep(__ENV.SLEEP_WRITE);
     }
 
     const key = __ENV.OBJ_NAME || uuidv4();
@@ -118,8 +118,8 @@ export function obj_write() {
 }
 
 export function obj_read() {
-    if (__ENV.SLEEP) {
-        sleep(__ENV.SLEEP);
+    if (__ENV.SLEEP_READ) {
+        sleep(__ENV.SLEEP_READ);
     }
 
     const obj = obj_list[Math.floor(Math.random() * obj_list.length)];
@@ -131,8 +131,8 @@ export function obj_read() {
 }
 
 export function obj_delete() {
-    if (__ENV.SLEEP) {
-        sleep(__ENV.SLEEP);
+    if (__ENV.SLEEP_DELETE) {
+        sleep(__ENV.SLEEP_DELETE);
     }
 
     const obj = obj_to_delete_selector.nextObject();