As you might guess, I get #copyleft questions all the time, & #FOSS developers being an inquisitive & intelligence bunch, they are sometime complex.
After 30 years, though, I have mostly “heard it all”, & I only get a truly novel & difficult question once every few years.
@giomasce just asked me an excellent question re: LGPLv2.1 (also applies to #GPLv2) that is novel & I'd never considered before.
I'll say what it was publicly when I figure out what the answer is.