I would so love to buy most of your assets but they are 16x16 and I need 48x48 for RPG Maker MZ. I know it is somehow possible with photoshop or plugins but I would just love to have the "normal" version
Yes, pixel art assets can be scaled up as long as you keep the proportions intact. In Photoshop you should activate the "nearest neighbor" option when scaling them 300% (to reach 48x48), or you can use some other software like Aseprite.
I can scale them, but it takes some time, which is why I usually just provide 16x16 and 32x32 versions. I'll see if I have some spare time to add 48x48 versions to my packs these days.