This one might be difficult to explain and I've no idea if anything can be done about it or even if it's a real problem.
First create a route and save it. Next change the route slightly and save it again with the same name. Close the route and open it again. At this point I am seeing the original route not the revised one. This I understand, it's simply a browser cache issue. If I shift+F5 the page is refreshed from your server and I now see the revised route.
Back up a stage to the point where the route has been revised, saved, closed and reopened but the browser has not been refreshed. If I ask for a GPS file at that point which route would you expect me to get? I expected the GPS file to match the saved revised route but it does not, I get a GPS file for the original route. My expectation of getting the revised route was because the GPS file isn't cached, this is my first request for it so it has to be coming from your server not my cache.
The only explanation I can think of relates to you mentioning in discussions about waypoint limits that the waypoints and hence the route are embedded in the URL my browser requests. When I request a GPS file does the browser send over 'give me the GPS file for a route from A to F with waypoints BCD and E'? This would be the route I am seeing and could be out of date due to browser cacheing. Or does my browser say 'give me the GPS file for route number 12345678'? That should always return the saved route.
I was expecting the latter behaviour and that was because I (wrongly) thought you have to save a route to get the GPS of it just as you have to save before you can print maps to pdf. In writing this and checking my facts I find I am wrong in believing I must save to get a GPS file.
So now I've realised the mistake is mine why am I not cancelling my post? If I create a route in the manner described above and download maps, GPS file and turn by turn instructions will all three match? I think they might not. The GPS comes from my cached URL I now believe. The route has to be saved to create maps so logically the maps are created from the saved route, this would lead to the map not matching the GPS in my scenario. Printing turn by turn does not prompt to save the route so I would expect that to match the GPS.
Am I making any sense at all?