Whenever a ConversationMessage was constructed, a warning was printed saying "Both point size and pixel size set. Using pixel size." Stop double-setting the font size and the warnings stop
This may be system-specific because I don't see where we are setting the font's point size. I will test this on a few different systems (I haven't yet) and I hope others will test it on their system!
Note that this is easiest to test when applied on top of D15979 so you can scroll up to cause more messages to be constructed