I have rather extreme movement in my ear canal when I talk or eat. I could never get anything generic to stay in my ear. The full blown deep seated earmold with the arm that reaches up slightly in the ear bowl is the only thing that will stay put for any length of time. Currently my problem is that the last one I had made at Costco holds onto the amplifier so tightly you can’t get it out in order to clean the channels with a pipe cleaner or something. Costco says I’ll just have to bring it back and they’ll clean it periodically but that’s just Costco’s poor handeling of a real issue. But the bottom line is your moles have made all the difference in the world as far as eliminating feedback and keeping the device securely in my ear.
I have found the Oticon Grip Tip (with an OPN1 miniRITE) to be a good compromise between domes and custom molds. The domes were always working their way out, and the molds seemed to trap and hold moisture. I started with the unvented Grip Tip and migrated to the vented Grip Tip and have been very pleased with the results.