I get what you’re trying to do and I wanted the same. I created a list of all the repeaters in my region, and those in the areas I travel frequently. I wanted to create groups to scan my home area, plus groups to scan other regional areas when visiting those areas. It’s true there are only 22 channels, but I wanted different area repeaters with their respective tones, so I wouldn’t need to fuss with it and could dial in a channel (that I named) and go to town. Now keep in mind, it’s technically not legal to use a Ham radio to transmit on GMRS frequencies, but I’m pretty sure you can listen with whatever you like. ;-) I didn’t find a “legit” GMRS portable, but the Icom ID-50 can do the job nicely. It’s expensive, especially compared to the China made stuff, but it’s legit quality. It has 500 channel capacity and can be programmed easily into groups using RT Systems software. I initially created two groupings, then expanded to three. You can have up to 100 in a group on the Icom. The software on device allows you to chose the group you wish to scan, or scan all groups. You also have dual watch / dual-scan options. Having recently got my Technician Ham license, I’ve since updated groups. If you understand the rules and chose to color outside the lines, you’d find the Icom products really really nice. I also like that it can charge in the car with USB-C. Best of luck with your search.