Yeah at the end of the day having all modifier on icon is comforting. But I think we can do it step by step. If Yuri provide at least to cover 60 for now, the next keyset only need to make the TKL and we are done.
Speaking of 60, there are 4 modifiers that don't have icon only yet: control, alt, code (yes there's winkey but..), and escape. Tab, shift, enter, backspace, menu and capslock already have icon only. I recommend following Granite icon mod for reference, which use meta icon (◇) for winkey/code and mac-style control (⌃) for simpler design approach.