The *easiest* non-nlt game to implement should be limit texas. After that nl omaha and pl omaha. If you implement omaha, omaha hi-lo isn’t much of a stretch as you only need to change the hand evaluation (and that code is publicly available from a number of sources).

Stud games could be a bit of a pain, due to the constantly changing positions and some occasional weirdness in hand strength evaluation.

Draw games might challenge the mini-hh somewhat (triple draw easily could have a player seeing 18 cards at showdown combined with 4 streets of betting decisions and 6 drawing decisions) and you’ll need some new hand ranking code.

From a profit pov the priority should be plo followed by limit texas, as those games are more common.

I do think that a lot of the work involved already have been done