What bothers me about the emit is that it makes it hard to "eject" the TS and be left with JS, and I can see it being bewildering to someone trying to debug the generated code if sourcemaps get borked.

But in fairness to the emit: it does support inverse lookups, which I can see being convenient.

Ron Buckton's proposal-enum has interesting ideas for getting that convenience natively in JS: https://github.com/rbuckton/proposal-enum