If your goal is to make the output prettier than the real thing, it's a good strategy. I'd also recommend rasterizing mode 7 at 512x448 in that case
The goal wasn't to do the output prettier, but to do things in line with all the other Arcade/Console HWs that does things like that (yes, it's a guess). If you've done tests on the real HW that says otherwise, then I'll go reverting it.