You are advised to use a full sized SD card rather than an adaptor for a MicroSD although some people break guidance on map updates of the 32gb file. Firmware is smaller. You'd probable get away with it. Suspect your PC doesn't have a full size SD why you are asking.
The firmware has proved to be reliable on installing straight onto older firmware / hardware in the past. One person did stop the process where it asked did you want to upgrade the FeC or something like that. It installs Mib Tools on that and continues running. If it ask you that question say Yes you want the whole lot. They then didn't get the long life navigation FeC since they stopped the process early. The package if left to run all the way thru gives you a complete upgrade. Basically if it deploys the FeC upgrade you get your existing FeCs plus the update extras.
If using a Mac best to obey the rules, use Keka and CleanMyDrive on the download on the card. PC just use 7zip.
The firmware has proved to be reliable on installing straight onto older firmware / hardware in the past. One person did stop the process where it asked did you want to upgrade the FeC or something like that. It installs Mib Tools on that and continues running. If it ask you that question say Yes you want the whole lot. They then didn't get the long life navigation FeC since they stopped the process early. The package if left to run all the way thru gives you a complete upgrade. Basically if it deploys the FeC upgrade you get your existing FeCs plus the update extras.
If using a Mac best to obey the rules, use Keka and CleanMyDrive on the download on the card. PC just use 7zip.