For the optics, you are right that a ‘tube length’ should not make a difference on an infinity corrected optic - the image is formed at infinity. However there is a known issue #158 that the infinity optics module is usually a little short - this is on my list to find out whether it is defined incorrectly or whether it is printing issues, or different back focal lengths of different nominally 50mm focal length lenses. The specified Thorlabs lens has a back focal length of 47.2mm, but the camera sensor surface is ~2mm above the camera board so the module is ~49mm from the back of the lens to the front of the camera board in that case. For an infinity corrected optics module it is very easy to check - take off the objective and the tube lens should give a focused image for objects that are far away. As it is usually too short rather than too long you can correct with shims in another thread on this topic.
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