User interface Playstation 4 on PC

[Raist]

you can set the size of the fonts for your chat also. Think it was nested somewhere on the Character config screens.

Edit:
Character Config -> Log Window Settings (the chat bubble icons at bottom)

On the General tab, the second drop box (Chat prompt font size) is for setting the size of text in your chat log. Don't recall any setting that will alter the size of character chat bubbles though. You can follow the cutscene dialogues in the default Events tab of the chat log though if you have trouble reading those popups. Forget if the dialogue from clickable NPC's show up there too or not. The random bubbles as you pass crowds don't though, which kinda sucks because some of the conversations are fun.