Regular letter case on screen. All caps is not as easy to read or scan. See, for example, this article mentioning ‘bad shape contrast’: https://uxmovement.com/content/all-caps-hard-for-users-to-read/
This way the user had the choice to use all caps if they wanted.
Yup, understood and we know about it. It might sound strange but the performance is the reason for having upper case only. It is the same reason as with the limited number of colours. The limiting factor is the antialiasing. We cannot afford run time calculations, therefore we used predefined bitmaps in RAM.
Firmware 1.2 and 1.3 brought in many optimizations in terms of memory usage and speed, I think, extending the fonts with lower case chars could be now possible. Will discuss it with @tomas.
Doesn’t sound strange at all. I can see how removing lower case letters saves on memory.