It's quite simple.So how is an xt perfectly useable in a Mac environment, what can u actually do with the xt? I don’t use and have never used Basecamp. You can’t see the xt files without using something like commander one.
So assuming you have a gpx, how would you get it from the mac to the device.
As stated I use MRA and transfer via Garmin drive, but that isn’t the mac.
If you have a Mac and a Zumo XT, then you can use Garmin Express to update the XT and maps, you can use Garmin Basecamp to create routes and send them to the XT, and if you want to access the XT as mass storage to view what's on the drive, you can use Commander 1.
The fact you don't do that doesn't mean it can't be done. Your method also work perfectly well also, but it's not the only method.
I use MRA and Drive also, luckily in IOS, since if I'd had an android device on my recent trip the option to use Drive to transfer files wold have failed.