Hi there. Very happy to hear about your interest!
All of the Retro Cybercity stuff is RMMZ compatible. You would have to slice a few of the spritesheets yourself to achieve the right formatting for RMMZ. Some packs also include 3x upscaled sheets to work in the 48x48 sizing. The last couple of packs have not included this formatting.
The reason not all of the packs in this theme include those extras is because I am assessing what extra options like this to include in my stuff based on whether folks ask for it, it affects sales, or it takes a lot of extra work.
I am open to adding extra options to my packs if requested. I am also considering whether to make the packs plug and play with RPGmaker going forward. I designed my other theme that way to see how much extra work it takes. It’s a lot haha. But maybe worth it if helps folks like yourself.
Let me know if this helps and please don’t forget to mention if you’d like to see more options. More people tell me that, more chance I’ll add them and the faster I’ll do it. :)
EDIT (04/01/24 – but not an April Fool’s Joke!)
All my work is slowly being converted to full plug and play RPG Maker compatibility (at 16x16, you’d still need to resize depending on your needs). This means the sprites no longer need the sheets reformatted or resliced to achieve this.