All the info you need is here Caltinor/Project-MMO-2.0#227 no sense in writing it twice.

I think this is probably going to be a hard incompatibility. Pmmo's vein mining works by listening to the break event for a "marked" block and if so, performs a player break (which is upstream enough for forge evens to capture those too) for each veinable block.

I'm guessing SG is also using these events and we end up with a circular reference. If my assumptions are correct, then I might have to add an item blacklist config for vein mining.

Sounds pretty accurate. The saw works as an independent tree cutting mod. So its not enchanted or anything like that.