Yes, there is Stem Maker in Acid Pro. But I think its quality is worse than using Spleeter which is free. At least it was with Stem Maker 1. I don't know if they switched over to the Spleeter algorithm with Stem Maker 2. If yes then they would be identical in quality.
Yes sorry I have been using it and used spleeter.. What I'd like to do is take a current track in a mix and (say) right click on it to split into stems.
Only difference I've noticed comparing the two methods is that with spleeter, when the stems are played together sounds the same as the source. The version in acid-pro seems to lose something when all stems played together..