Collimation Issue

Your secondary is slightly rotated relative to the focuser, you can tell that because it's not perfectly round. This is the hardest adjustment to get perfect just because of the way most secondary holders are designed. I think it's possible that all the time and gadgets are making you over think this. Have you done a star test? Are the rings concentric at high screen magnification? Are you having a problem with star shapes or irregular illumination that's effecting your images? That's the bottom line, it will probably never be absolutely perfect in some collimation gadget, it's your images that really matter.