Hi George, we must be literally doing the same UI at the same time. I have just run up against the exact same two problems. I tried copying the font file into the src/fonts folder manually but that just chucked up another error to do with not being able to find lvgl.h in the parent directory. I backed off and deleted the bigger font text box and put it in the "fix that later" bucket.
Regarding the float I think the way to do it will be to operate in integers, store the integer in your controller, then have it converted to a float in your code and then pull that number onto the screen as a text. I couldn't find any way of getting Squareline to handle decimal places other than when I tried using the spin box, which kind of worked but also highlighted the decimal - as that's kind of its purpose. That might be a way forward if I can find a way of stopping it highlighting the decimal but that also threw up an error in the code to do with styles. I deleted the offending line out of the generated code and then it compiled but it felt a bit messy and probably not the way forward.
I see we are both using Mac as a dev platform - I sometimes worry that might be an underlying issue.
To cut to the chase this is what I'm trying to replicate on the controller screen:
I'll be going back to it tomorrow. To be fair I only found out that LVGL existed on Friday and Squareline Studio shortly after, so I'm pretty stoked that I've got the bare bones of a UI on the display shield already.