(lowest priority) De-level / Stopping EXP

I'm curious if its possible to stop all exp to stay at a certain character level by a variable change that a GM or Dev can do, or if its possible to use a bug to not gain exp.

for example, I'm currently working on a low level project but i want my level to max out at level 12. if its possible to stop my exp or level like i could a gem, that would be perfect but obviously we dont have that option.

I know in the past there were items that could de-level you, however, i know it is currently not possible. So if there are any new suggestions or any way i could get a solution to this, that would be sick.