Allow snapping to objects that are masked out and also make opacity mask objects visible in outline mode
For example, if you draw a large box and place it completely inside a small box so that all four corners of the larger box are masked out, then try to drag a guide it will only snap to the smaller clipping mask, the guides wont snap to the larger box unless you hide or release the clipping mask. Also, as an additional feature I think it would be of benefit if when inside the opacity mask, when you go to outline mode you could then see the objects within the mask.
Supporting videos below
Egor Chistyakov commented
Well, it could be useful, voted.
Although I would rather prefer an option to hide clipped stuff at all and stop snapping to it: https://illustrator.uservoice.com/forums/601447-illustrator-bugs/suggestions/35504488-outside-of-clip-mask