There are plenty of topics that folks "frown upon", IMHO, based upon over the top paranoia and irrational misunderstanding of how the market really works.
Shelby "clones" for instance. Some people think they devalue the real ones. That's utter nonsense.
Same for fastback conversions, they don't devalue the real ones whatsoever, but you'll still find some Chicken Littles out there claiming that the sky is falling.
Of course, fraud and shysterism and shenanigans have no place in this hobby, or on this planet. But as my grandfather always loved to say, you can wish in this hand, and sh** in the other, and shysters will always be lurking out there, it'll never be utopia, so caveat emptor. Any time you're purchasing a 5-figure toy, you'd think that you would do a bit of basic research, like learn where the body code is in the VIN ferchrisake, before scratching your check.
So just ignore the Chicken Littles, and make sure you're always up-front in relating it's been converted, should anyone ask or should the car ever be put up for sale. If the world all of a sudden starts running out of coupe projects, man, I'm in trouble! LOL... Eventually, the new generation of "projects" will be all of the coupes that were restored in the 80's and 90's that just weren't done well or right, and it'll be time to tear apart and start over. We just keep recycling, which is why the classic car hobby is actually quite "green".