Yes, the Roomba 675 supports the same Open Interface Spec as the Create 2. You won't get the custom faceplate with mounting hole locations. But you can download the locations here. Remember the serial connector is under the faceplate, then you are good to go.
First the disclaimer - if you modify the robot by defeating or replacing the protection features you're on your own.
That being said here is some useful information that will hopefully help you make good design decisions.
The fuse is actually a PTC. The benefit is when you eventually accidentally short battery to ground in your project the PTC protects but ...