Properly noting a "benched" defensive player

[AtlUmpSteve]

Follow everything Mike said above; 4.3-E makes clear the DP can play ANY defensive position. Substitution rules allow them to announce that the DP will catch at the plate meeting, as soon as the PU accepts the lineup as official. That makes that person the catcher now listed on the lineup in the top of the first inning, in addition to being the DP (a move allowed by the definition of DP, because 1) that play was initially listed in the lineup as the DP, and 2) that position in the batting order is now "twinned" with the FLEX for the purpose of all DP/FLEX movements).

Once reported as a defensive change prior to the start of the first inning, that person is now the player "listed on the lineup as the" catcher (ASA 8.1-B). It meets every requirement of the written rule, and is not specifically excluded by any other rule, rule supplement, or interpretation by the NUS. Therefore, it is legal, and must be permitted.

Is it a loophole? Possibly; but we aren't permitted to interpret that this isn't legal, either. Only the NUS can do that; and to my knowledge, has not. Since it isn't completely new, perhaps you should consider that the NUS considers it legal, too?