The actual damage is that it's pretty common (my last team has this happen) for a team to setup a cert, verify it works, and then when they deploy the cert it works some of the time or "works on my machine" and so the failures seem really random and by definition hard to reproduce because you have to restart chrome to reproduce.
Probably the tl;Dr is that validating against a persistent cache like Firefox is fine. Validating against an ephemeral cache with chrome is likely to cause a lot of breaking.
Probably the tl;Dr is that validating against a persistent cache like Firefox is fine. Validating against an ephemeral cache with chrome is likely to cause a lot of breaking.