A generic JRPG engine? Very cool. Plan to port it to something other than GBA, or set up a Patron/GoFundMe/whatever?
uh... ask me again in a year lol
There's a third option - besides hardcoding all engine features while having a minimalist scripting system, or having a minimalist game engine with a more powerful scripting system - modules/plugins. But that requires an API, doesn't it?
Some sort of module system did actually come to mind at one point. But I think the best way (for the use cases I can think of) might be to open source it and just make it easy to extend, and for pre-made "modules" do patches similar to suckless tools.