Very nice work on the camera mount.
Consider building a tube-hood providing some gap for the lens to float in, and affixed near the film side (instead of the lens itself). It will avoid the additional arm from the tube-hood weight on the lens mount.
Even for light weight PLA, a long arm on the sensor can enhance vibrations.
Here is what I built for 8mm.
A Tube slides on that providing cover for the lens inside the hood.