How hard is it to comprehend (and mind you, it is documented and has been pointed out for your discretion) that a mud ring is for mounting a flush-mount device flush with a finished [wall] surface and covered with a wall plate.
The glaring flaw in this berating chiding jibe of yours is YOUR ASSUMPTION that something that looks like a mud ring, to you, HAS to be a mud ring in spite of a major manufacturer, AND UL itself, together, listing and labeling it as a "device cover".
A mud ring is not intended to be used for surface mounted outlet boxes.
You have shown absolutely no documentation of this intent as being all encompassing for anything that "looks like" a mud ring and that the intent is absolute and without exception. And, until you can show that the Raco product line is something other than what it is labeled and listed as, any statement of yours of this type is without foundation, and meaningless.
To defend a position otherwise is nuts from my perspective... including the concept that a mud ring is not a mud ring simply because it is not listed or labeled as a mud ring.
This is obviously your opinion. We get that. That, and a quarter, leaves you with twenty five cents.