Thanks all for the input.
The m20/m30 series whatsminers seem to not have anyway to disable AB. As for S19 and the like it seems that there is no way to go without AB else the older machines seem to throttle down hashing by over 50%.
There's nothing we can do with Whatsminer units have you tried to contact their support and ask for older firmware? I think their old version doesn't have ASICboost yet.
About s19 have you tried to use Braiins as suggested above? You can able to disable AB but I don't think it throttles down the hashing to 50% it depends in your tune or just use auto-tuning and let the braiins set power and frequency for you while AB is disabled let see what's the difference if you enable and disable AB.