Working on Sun heavy iron, boot time was excuciating. We’d add RAM to a fully pupulated E3000 and then waiy 40 minutes before the first diagnostics appeared on the terminal.
That wasn’t technically boot time, but the OBP equivalent of POST.
Honestly, OS boot time has never been an issue for me.
I don’t have a strong opiniion on the matter, but it really seems like it would encourage stalking and revenge-downvotes.