Yes the aircraft are close enough to fit either molded case. The original molded foam inserts for the two aircraft are the same in most respects, yet are slightly different in one. Either airframe will fit nicely in either insert, however the camera/gimbal support is different to accommodate the different dimensions of the CGO3+ and the C23. Therefore the wrong insert will not properly support/or even allow the camera to fully seat. The problem is this mismatch obstruction is out of sight under the body so it is something that is not obvious until you try to force it closed.
Aftermarket cases would be trial and error depending how the the camera support area is cut or molded. If it is using open cell foam, you could easily make modifications to adequately support the camera/gimbal.