Option to limit pRuntime CPU utilization in benchmark mode

[l00k]

Is there any change to get option to limit pruntime utilization in benchmark stage?
Cuz it sometimes makes unable to access runtime server or even entire machine.
I understand idea at current stage, but let say reducing utilization to 90% by adding some sleep period in benchmark loop would left some resources for server - so PRB could freely access it.
I would prefer reducing benchmark process to 90-95% rather than leaving 1 core for that purpose.

EDIT:
Interesting thing I discovered which seems to confirm need to limit utilization - I connected into worker machine and tried simplest endpoint curl localhost:8000/get_info
Sometimes it takes really long to get response (I have noticed even 160s).