ROM Hack Is it possible to remove the screen gap?

[laggerific]

Is anyone familiar with projects that try to remove the screen gap for NDS games?

For instance, Mr. Driller has native gapless screen support, so when you are playing it in DeSmuME it looks super clean.
On the other hand, Contra 4 has an unfortunate seam where the two screens collide.

I'm curious if this is something that people have attempted to address in the rom hacking community. I'd imagine someone would have done it for Contra 4, by now, if it were feasible...but, not sure if this is an area that rom hackers have really ever explored.

Thank you.

EDIT: I understand that art assets may have the gap built in, which would likely require some hacking beyond mere asset replacement...but, is it doable?

 

[FAST6191]

Depends how it is done. A few games I have looked at had nice little loops to account for the differences when animating between the screens such that things did not immediately go from one to the other. Such things could be altered but would be some effort to do.

If it is just a matter of fiddling with some background art that would be a different matter.

If it is mostly for emulators though then doesn't desmume have a little gap support feature as one of its options?