After using terminal monitor for a while I've decided to review feature list, or more specifically get rid of the stuff I don't use. And add screen instead.

It is not a big screen, only 8x21 symbols with tiny font, however now tool can be used completely offline. At least to see serial output from target device, you don't need web app.

This is how it looks like in practice

Side effect of those changes - I were able to make the board DIY kit like. This way I hope to lower the price at least twice!