no, i don’t think there’s a way to do that due to the fact that you have readers customizing the name and you’re trying to use overlays.
but an alternative would be, to use episodes texting feature. it doesn’t keep the name up there on the top of the screen but instead displays characters name as the texts are revealed on the screen. check it out and see if you like it!
also may i suggest you could use nicknames and upload overlays of the nicknames to use instead of an actual character name! for ex: bff, boyfriend, mom, etc. 