My left ear isn’t bad, but I was wearing a double dome in that ear, as well as the right, until I recently got custom molds. I don’t think it was a bad thing to fit you with double domes; nothing wrong with trying to preclude feedback, as long as you’re comfortable and not overly occluded from wearing them.
Here’s the market share of the major HA companies as of 2019:
GN ReSound brands (ReSound, Jabra, some others) do seem to be mentioned on this forum less than might be expected based on their market share. Maybe that’s because their connectivity and app (and accessories, from what I’ve read) are fairly trouble-free, and their hearing aid functionality (noise reduction and such) is good. I was wearing ReSound Quattros until I got Whisper aids almost three months ago.