We have spent a lot of time looking at ways to be able to download courses, but the management of individuals’ courses lists became too complex. I could write a long paper on the issue, but time is against me ;-(
We are also severely limited by the amount of storage on the watch, so we are planning to approach the problem in a different way.
Rather than enabling routes in the GPX file we are planning to allow you to build your own course at race-time by selecting marks in sequence from your downloaded marks list.
It’s in the development plan.