Depends on the tester really. Although it was last year but few friends in the nct said there's no issue at all in any sort of rollcage once it doesn't obstruct access to the car i.e; it can not have door bars.

A harness is fine once you still have conventional seat belts too.

Car being stripped out is no problem once there's no sharp metal work, wiring or anything exposed


Some testers might want an engineers report for the above alright but that it's too difficult to get either and nice to have for your insurance too when keeping everything legit