More of what Frankie said. I'll try and keep it straighforward.
1) Create your route in MM.
2) Open properties (or right click on route & select properties) Name your route e.g. 'FRED' (the default is Route)
3) Save As 'FRED' (to somewhere where you can find it! e.g. desktop) using the dropdown to select .gpx
You should now have a file on your desktop called 'FRED'
Connect the Edge
After a couple of moments and bleeps Window(s) will open on your PC desktop.
I have 2 ... E: which is the internal memory and F: which is the Memory card
As F: contains your mapping and other files which should be left alone (Frankie - me too
) close the F: Window
4) In the E: Window there is a folder called Garmin. Double click to open revealing several folders & files
5) Drag and Drop 'FRED' onto the folder called GPX
6) Disconnect EDGE and switch on allowing unit to aquire Satellites
7) Press Menu, Select Where to? then Saved Rides
You will now have a list of tracks including 'FRED' from which can select and Navigate.
If you didn't rename the Track as in 2) above, even if you did so in 3) it will show as 'Route' and not 'FRED'
I have just tested this sequence with my 705 and it works!
There has to be a better way, and I think the ball is in Memory Maps court now! Before the advent of the 705 I was working on a method using Courses with the 305 and successfully loaded (and rode) a 200k+ Audax, one which would have exceeded the 100 waypoint using routes. In the meantime I have reverted to using the good 'ol routesheet using the Edge as a recorder and finder of ATMs (for proof of passage) at which it excels!
All that said, it is an excellent bit of kit (best so far in my experience - Edge 305 and Etrex Vista) and no doubt I shall be wittering on about it for some time to come - epecially the Autorouting, which leave much to be desired!
Hope this helps
Andy