Hello, for my Bachelor thesis I'm making my first variable font. The font is for Pivovar a techno organisation that organises raves in an old brewery. This is my first font so I'm new to font design that's why I only did capitals and numbers.. At the moment I'm only using the x-height as variable but I will be adding a weight and width variable. I wondered if anybody had some advice or tips for me?
This is my regular font:

This is my flat master

This is my long master
Comments
Thin diagonals in K and S are too thick.
I like the shape of zero but it winds up looking light and narrow in the Flat master. Flat four is also light, but wide looking. I’d consider a three with a notch shape on the right side.
@Sander Pedersen, thanks for the feedback, it helps me a lot! I'll work on it!