My biggest problem with clipping is with metric survey files in metre units. I am still trying to work through the issue to find the best work around.
Survey files need to have precise geometry in relation to a known datum, so can’t be dumped in at the origin (without determination of the exact origin shift, etc.). I always move the model by a convenient and simple N, E shift to get it close to the origin, otherwise the screen rendering is wobbly due to the huge coordinates.
I sometimes find that clipping is worse with perspective on.
It also seems that clipping occurs when you view the model from a particular quadrant. If you position the viewing point to a different quadrant in space the clipping doesn’t happen. That is pretty limiting, however, when manipulating the model for editing.
Scaling up the survey by 1000 seems to eliminate the clipping. Reducing the window accuracy by 1/1000 doesn’t have that effect unfortunately - I wondered if it was an accuracy issue.
Unfortunately, scaling by 1000 is only convenient if the scaling can be done relative to the origin, but that requires putting an object at the origin to “anchor” the selection, or manually shifting the scaled selection after scaling. Then the model is not true to its units.
There’s still something very fishy about the internal calculations that results in clipping. I can’t believe it can’t be solved by revisiting the internal methodology. Clipping has to be the biggest bugbear of Sketchup.