I guess you never had the experience of maxing out the wrong item, then?
What about building a really nice, fully fused mech, then see it turned to brick because it got hit by NERF update...
Then this suggestion would be really useful, eh?
It's not just for the top players. Even Free to Play players with limited item and inventory could benefit from this. Example - I have only one fully fused torso. What if I want to "convert" this new torso I got? Does that mean I need to take months to make it fully fused, too?
But, you are right. Developers would see this as a bad business move because people will not "buy" stuff if they can just swap out their fully fused stuff instead of buying tokens to max the new items up.