The issue is that Wilcox did not originate the specs or tolerances for the "Universal" shroud-to-mount interface, it was born back in the dark ages of the OG PVS-7.

And while Wilcox does control the specs and tolerances of their own mounts and shrouds, for obvious reasons, there's a desire to maintain backwards compatibility with legacy systems that have been being produced by multiple different companies with varying degrees of quality now for over thirty years, and (e.g.,) an L4 G24 needs to be able to fit not just in a Wilcox produced shroud, the Skeleton and VAS shrouds usually mounted to Ops-Core FAST helmets, to cheaply produced pot metal PASGT ratchet strap mounts and everything in between.

Likewise, every Wilcox shroud not only has to be compatible with the latest and greatest in NVG mounts, but it needs to be able to accept even this monstrosity:



Unfortunately what this means is that tolerances have to be a little bit looser to maintain that backwards compatibility, and essentially always will be until someone invents a new, proprietary shroud/mount interface that becomes widely adopted--something both Wilcox (L3 interface, Rail Mount) and Norotos (TATM bracket) have tried, but both eventually found that end-users continued to prefer and insist on a more universal mounting interface.

This means that a) tolerance stacking will pretty much always be a thing (some mounts need to be hammered together, while some will have some rattle depending on the combination) and b) shimming if necessary is going to remain a common solution to tolerance stacking woes.

Why no one has ever made an adjustable tension mount, I couldn't answer you, but if shroud-to-mount rattle is a significant concern, then the best solution is frankly the Wilcox hard-mounted/semi-permanent solutions which have been favored by some end-users.

~Augee