Note: I just meregd 2.11.0 for the next Ubuntu release, so patches against that are fine to get things started - but should have some sort of upstream backing to not end up as maintenance dept.
I know how this feels with my german chars äöü sometimes causing such things and you feel nobody case about you (cyrillic in your case), but without an upstream-ack on this I'd consider the risk to high to cause more regressions later on (especially as I have to admit to not use amavis a lot, so my risk assesment would be guessing at best).
Note: I just meregd 2.11.0 for the next Ubuntu release, so patches against that are fine to get things started - but should have some sort of upstream backing to not end up as maintenance dept.
I know how this feels with my german chars äöü sometimes causing such things and you feel nobody case about you (cyrillic in your case), but without an upstream-ack on this I'd consider the risk to high to cause more regressions later on (especially as I have to admit to not use amavis a lot, so my risk assesment would be guessing at best).