I checked the file again and your post. It looks definitively better with G2/G3 radius on the cube.

In order not to do this model for the 12 time hahahah, I mean before proceeding to use that technique. Do you think by making the cube with different continuity on the radius I will solve it just doing sweeps (intersection as rials and two curves as profiles). If you believe this will reduce the amount of time of re-tweaking ...I will do it.

Just want to know your opinion.