This procedure is being taught at one of the leading SIM centers.
It does complicate the sim session, when doing the NPA CTL, if the mins are set at MDA, and you can not descend below MDA +50.
Make of it what you will.
Can not see how it makes the dirty dive less likely, but whatever.
I use this procedure all the time. Minima is set to MDA+50. All the calls are relative to MDA+50. In otherwords as far as the crew is concerned, the MDA is the chart MDA+50. Not complicated and I have never seen any issues with the concept.
The reason for the +50 isn't stop dirty dives, but to help ensure that a CDA heavy aircraft doesn't sink below MDA during a go-around due to the inertia of the constant descent at 700fpm. Something that wouldn't happen if you were level at MDA when reaching the MAPt. We don't add 50' to the minima for a circling approach for the same reason as it is permitted (i.e. assumed) that one will be straight level prior to the MAPt.