24k Topo from 5x to 5x+

Well if you buy the card the map is locked to the card. If you buy the download it's locked to the device. It mentions this on the web page where you purchase it.

I'm aware that it mentions this on the website. This is on me, but my point is that Garmin would be much more likely to capture a bit of additional revenue from me if they made map purchases for the Fenix line a bit more portable. Honestly even a system that would allow you to remove it from one device and add it to another would be good.

Try making that suggestion here https://www8.garmin.com/contactUs/ideas/

I copied the 2018.10 cycling maps that were recently rolled out to the 5x. I copied the .gma and .unl files as well.

The reason I did this is because the 520 plus came with 2017 maps and no option to update.

I backed up and deleted the 2017 maps from the device.

They work on the 520, that's all I can say really, so i still maintain it's worth a try, nothing to lose, all to gain.

Yes, but that is not the 24K map. It will not work.

Did you purchase a download or did you buy it on a card? The download is locked to the device so isn't transferable

Wow this pretty insane, thank you for clarifying.

Yes, but that is not the 24K map. It will not work.

Good observation. It is however a device locked map with unlock files and yes, it did indeed work.

I also just moved over a pre-installed topo map with unlock files from my 5x and that worked too.

So why would any other map be different?

Because they are. Some are not but numerous maps are including the 24k Topo maps.

The 100k map is not as detailed as I'd like for when I'm backpacking in the mountains. The OSM versions I've looked at do not have as many routable trails in my area, particularly where I backpack generally in the summer.

Have a look at the talky toaster maps.

https://talkytoaster.me.uk

Talky toaster maps are no better for that as he takes his data from OSM mapping, and for some you have to pay.