I’ve been lead to believe that if a speaker is underpowered that you can damage a woofer, and I assumed this had to do with DF...An amplifier that is underpowered relative to the application, and therefore may be frequently driven into clipping, can cause tweeters to be damaged. I am not aware of any means by which an underpowered amplifier can damage a woofer, or of any relation between damping factor and the likelihood of speaker damage.
Regards,
-- Al