Ok so some things I can say
Heatran is planned to be a futa, BBW is pending tho seems to be chainsaws proclivity's and the already round design can speak towards that
Giritina seems to be leaning BBW with the other forme being thinner. I feel that Dialga and Arceus would not be BBW because they are generally more slender in design, especially Arceus.
After each update chainsaw takes a week or two break to work on their other side project (the vore runner one you see on their page) to avoid burnout so basically all chainsaw has rn is ideas for 4.2 and that's about it. idk how long the next update will take but hopefully less then last time due to there technically being less mons to work on rn. That is to be seen tho