If You look on the thingiverse files, check the bottom side of the bumpers. its not like its missing, but in my opinion it should be, well, there should be stiff crosses plates to hold the motor screws. so the side view of the arm with motors would look like : screw/some stiff plate, cf, or anything/ bumber/ carbon arm / motor. without it , Youre basically screwing the motor screw into the bottom of the bumper ( which is TPU, so its soft). it works, but properly should be mounted as I stated above. as to the performance, it not light , Im getting around 3 minutes with a 1000mah 4S. Would I use it to freestyle? If I would have no any other working quad, then I would just remove the bumbers ( 25g each AFAIR) and go for it , thats for sure, but for freestyle I would rather choose different 3" frame, BUT cinerat gives You option for those bumpers which arent ducts, so it is heavier, but still acts more like a normal quad rather than whoop ( especially in yaw authority). so , for a mini freestyle without big dives where You would might need more power to level out, yeah its possible. for me its quite fun, although not freestyle but more cine , Im still getting used to the high kv sound LOL , still in the middle of setting the correct pids. hope it helps

Yo JUSTiFLY_FPV you can check those crosses on TBS cinerat page, theyre on the photos