I initialy didn't want to upload the modified config file because I don't want to get into legal troubles with the Retevis Company. But since I got a few private messages recently, asking how to enable the high power mode or select different frequencies, here is how:

Just download the official flash tools for both the PMR and the FRS version of the radio here, install and start both programms, export the default config files from each of both, diff/compare the files with diffchecker.com, NotePad++ or something and you'll easily spot the difference between both files. It's not just one bit though, the settings are kind of spread out across a few locations in the config file! Btw the flash tool is a little buggy, make sure to set your Windows Localisation Setting to US!  Have fun and let me know if it worked :)