Lust Theory S3 is not needed , the sex scenes are good sure but the story is not anymore , didn't even finish S2 because of how bad the story was.
Lustyverse : Passion on Display is for people that like being cuckhold for now , so not needed as well
Returning to Mia i haven't even finish the story yet because it just got boring after all the mystery was revealed , i have it downloaded but after the mess Inceton games have been writing wise and after reading some comments in it's comment section probably not worth finishing it as well. Why a 3rd Mia game tho? Just let Mia rest forever before you ruin it more .
As for the new game , not expecting anything good from it story wise at least.
And for Shackbang remake , either will be better than the original or worse , we shall see