It's a bad suggestion to be honest.
How on earth will we monitor people who are doing bad stuff around forum if we automatically remove their warnings?
The system is working good, and there is no such thing as 1 month rule. People get their warnings removed in 1 day. It's all up to you. If you come to high staff swearing to remove your warning we will say apply after 1 month, but if you accept your mistake, simple say sorry or explain why you did that BOOM your warning vanishes.
System is good.
Suggestion Rejected, no need for further discussing because of obvious reasons.
"Request to remove your warning only after a period of time which would be at least a month and also only if you have learnt from previous errors and that it will not be happening again in the future." - This is not a rule, this is a tip.