Thank you very much! The way rank 6 looks will depend on the characters of course, but Nightmare is certainly among the biggest ones ^^
There should be an optimization update sometime within the year.
The next big update will focus on optional content, party events and more boob content (chibi BE in particular!), but I don't have a date for this one right now. I'm also dealing with some (good) IRL stuff currently which makes it even more difficult to estimate a date, but as soon as I have one to share, I will ^^
I do post monthly public devlogs on my Patreon if you'd like to follow the development there!