Try to write the above with pen and ink and then tell me if you can read it back yourself.
Single letters is not a good system but it was the less bad one.
Yep, that’s what it usually boils down to. However, I think a slight approach shift for basic materials could be useful, where introductory books / papers / … write out formulas. That makes it easier to understand the basic concepts before moving onto the more complex stuff. It should be easy to create such works, as they are usually created digitally, and autocomplete is available. Students can and will abbreviate those written outs words by themselves (after all, writing is annoying), but IMO reading comprehension is the key part that can be improved.
Also, when doing long formulas that you want to eliminate members of, writing stuff out can be a nightmare.
