I recently started designing a 3D printed case for EMS carts, they've got my embossed emblem on them but if people thought it would be useful I could do a version without and post the stl file for others to print.

I did it with a GBC clear cart.
Did a bit more sanding / dremmeling than I would've liked but hey, this cart is much sturdier and nicer looking than the flashcart's original shell.
No modification to the flashcart. Just modded shell swap.

As far as tips, just get an exacto, a dremmel tool, an empty cart and some time.
And don't rush.

I imagine Kirby's Tilt & Tumble's cart would be better clearance and it can be used in everything with that back corner notch that the clear color carts don't have.

I've done it. I made a video about it, but either deleted it, or made it private since it was terrible and unprofessionally done. I had to replace the EMS battery with a normal GB cart battery to get clearance (so it's already not ideal) , then I had do dremel away at the inner lip of the "label" half of the shell to have room for the SMT capacitors near the edge.

Nope. The EMS cart is bigger on a few points. It can be done, but you end up sanding away a lot of the inside on various sides. It's quite some work.

is replacing the EMS GB USB case as simple as it sounds?
All i need to do is find and old GB cart shell, dremel out a slit for the USB, right?

Just making sure. I couldn't find a guide online and I wasn't sure if the EMS board would fit in a normal GB shell.

If anyone has done this, do you have any tips?

Thanks!