I'm using this item:
https://www.amazon.nl/-/en/dp/B07DC7HWS ... 170&sr=8-1
It may look as if falling apart but it's pretty solid. To fit into the internal port it needs to be rather flat - this one fits. And technically they don't have to do much. And it's USB2 speed. Running now for 6 months flawlessly.
You could of course use the front USB port. Theoretically it should work. Practically I observed stability issues in the microSD/USB adapter combination with the SLC microSD in the front port. No idea why. They were all gone after using the internal port. Backups were never an issue in the front port, but running the database there was somehow, even when using an external HDD. Maybe it was just my device.
I started working on the internal port only because of these stability issues with the front port.
The other thing is, if you were using the front port for running the database, the internal 1 GB SLC would be bare, unused ...
You could remove it and use it for backups in the backside USB port. If you replace the internal USB stick, you can also use it for backups in the front port.
Why would you want to re-import exported data ? (there could be reasons though).
You can restore a database backup you have made earlier (best just before shutting down the system and replacing the internal USB stick) - once the internal USB is replaced by the microSD card and the system restarted, you can just restore the database. It will automatically end up on the SD card. But don't forget to save your system configuration before (System/Administration) - you will need to restore this too !
You will also have to save the content of the \\METEOBRIDGE\data directory tree (otherwise all non-default data will get lost: templates, scripts, exports, ....) - and copy it back once you have the SD card installed.