It seems pretty clear both devices were bricked by GarminExpress loading files to them that are incompatible with an Asian device, maybe a voice file. I already suspected that the Asian Garmin Updater doesn't communicate in pre-boot so that's no real surprise.

Best just deal with one device at a time, go with No 2 as you said. It's good that you have pre-boot access and the following is what I'd now do if that device was in my possession:

Try QuickCure3 to enable MSM if you haven't already, if that doesn't work then move to Cure3, make the cured 172201000410.rgn and load with Updater.exe in pre-boot. When you have MSM access, make a full backup of the internal memory including the .System folder, then look for any files that have been added by GE and delete them from the device, identify the suspect files by date and time. Hopefully you won't have to format and start again but if the file system looks corrupted or it's too confusing to know which files to remove then use only RMPrepUSB for re-format, then you can restore some basic (i.e. safe) files from the backup if required (some 2xxx series devices won't boot empty). Then load original 172201000410.rgn, if it boots up normally use Laucher.exe to invoke the Asian Garmin Updater program to check for updates and replacement files. Don't use GarminExpress.

Don't proceed unless you fully understand the above. Please ask questions first if unsure. All is at your risk of course.