I'm not Sierra, but, as someone who has experience in minor RPGMaker projects, I think I could reasonably say no. Unless she has already put this system in place, and for some reason, not allowed us to use it already. I don't think she has. If she were to make that change, it would take many hours for just a simple QoL feature because she'd have to go into every dialogue that mentions the MC's name and change it to a script caller, which is easily thousands of individual dialogue boxes by now.
yeah thought as much, well unfortunate but expected if u have the time, do work on such a feature, it may not seem all too significant but something as simple as a name could do a lot for player expression though the game isn't lacking any of that currently, that little feature would be a nice touch and if it happens, do expect to see my 10 dollar tier bump up to 50. Oh and ps thanks for replying and I'll continue to support u no matter what :)