clonazepam is fairly strong imo. i have a small benzo tolerance, and i can still get quite a buzz from 2mg. certainly enough to knock me out if i need it.
im on subs about 6mg once daily, clonazepam 1mg once nightly. if i take my clonazepam and vape some good weed, i really get quite a strong buzz.
i was about to suggest weed, but i see your name is "budder_smoke" which leads me to believe u probably already know enough about weed. a strong heavily indica strain may have just as good of a sedative effect as the clonazepam. just have to find the right strain/phenotype. i understand tho if u cant smoke due to being tested.
all thats gonna happen if u take 2mg clonazepam at the same time as your methadone dose... you will fall asleep and/or be groggy as hell all day. its not going to magically make u buzz hard from mixing the two, but it effects everyone a little different. in fact mix the two a little too much and u could cause harm to yourself.
if i were you id stick to playing around with weed IF u can. u wouldnt want to end up addicted to benzos too. just my $0.02...