The 3d res has never been very problematic to increase, even before the recent rerelease. You could increase the res on the original game too, it just didn't make much of an impact to me, because the lack of detail in backgrounds always overshadowed it, at least for me. In fact, the difference in resolution between 2d and 3d makes things look worse to me. Ff8 on pc has the same problem.

I always had the pre-rendered backgrounds in mind when I talked about improvements, sorry if I didn't make that clearer.