My recommendation are not very complex to achieve I believe and I think that they will make the overall user experience much better.
Some key features I would like to see implemented in the near future:
1. Ability to draw vertical lines by holding pencil at endpoint (see image for clarification)
2. Ability to draw orthogonal lines (also increment of 15) by holding one finger on screen while drawing (like it's done in procreate)
3. Simple gesture to faster manipulations (two finger tap to go back, three finger tap to move forward, four finger tap to hide or show menus (e.g procreate: I think that these simple gesture should become standard on ipad; they will vastly improve the workflow.
4. Make2D (like in rhino) and be able to export vector lines to pdf / export image without background (this second feature can be really useful if we want to render manually using a painting app)
5. Quick access to world-top C-plane (reset camera) + quick way to change view. The current way is a lighter slower. This feature is important because the C-plane changes every time we double click on face.
6. Implement more viewing options (top, bottom, left, right, parallel "N,S, E, W") also wireframe, shaded, technical, rendered (limited to colors only). Change background color.
7. Simple shadows in rendered mode (like in sketchup) this one can particularly be useful to arch student.
I heard colors + transparency were coming soon so I am very excited about those (extremely important for Arch student)
This one is not a feature, but a change which i hope will be implemented
I notice whenever drawing a line that right after I lift my pencil off the screen the dimensions disappear. I think that the dimension should stay for a few second just in case I want to input the dimension of the line manually. Also the dimension should reappear after I have selected the line (right now i need to tap the line twice for the dimension to reappear).