As I said before, I am NOT a fan of through mortises. I just don't like the aesthetic. However, I know some woodworkers do like them. To try to put this one to rest, I made some through mortises with the Domino even though it is not intended to make through mortises. Wood species is cherry and it was ripped to a square blank approximately 22mm thick. Domino was set for tight (small) mortises at a depth of 28mm with a 5mm cutter. Below are pictures showing the unvarnished (pun intended) results. Unfortunately the Domino cutters taper and become thicker once you get past the cutting portion of the bit so as you can see in the 1st pic there is some damage to the wood fibers on the flat part of the mortise as the larger than 5mm cutter shank left a detent (crushed wood fibers) in the wood - this never happens with non-through mortises on the Domino. Other than this, the front side looks very clean to me. On the backside, I do see the hang-ons, as Jeff calls them, on the curved portion of the mortises, but the flat part of the mortise is NOT clean by my definition (or eye). IF I wanted to make through mortises, I wouldn't be happy with this personally, but that is just me. I suspect there is some runout at the end of the Domino cutters and/or variability in cut as the cutter oscillates side to side that is causing this uneven cut. Bottomline is that I don't see the Domino as a suitable tool for making through mortises unless you like to look at glue/wood filler in the gaps of the joint. Perhaps the MORTY is a better option for making through mortises compared to the Domino, but in my opinion more needs to be investigated to determine how to get the cleanest, best cut possible with it. I expect that MORTY does everything it is supposed to do and does it well. However, customers will probably want to experiment with different router bits, routers and guide bushings with it to get the best possible cut should they decide to make through mortises. Might also need a sacrificial backer board to minimize tearout, hang-ons, etc.
Front of Mortise (Domino plunging from this side):

Back of Mortise:
