As others have commented on this and other threads
(see Dr Rock), if you have a ton of tracks in your route, use one of the handy utility programs (gpx2img, igfromgpx, etc) that convert all your tracks into a single map file.
On a recent 2300mi trip, I had over 50 planned tracks, so didn't want to "show on map" each track. Instead, simply created a small transparent map overlay that quickly loaded at boot time for my active off-road profile. I was also able to easily share the img file with my co-rider who had a Montana. Very nice solution.
I also use this technique to show all the various "tracks" for my local ohv area.
I think the "show all tracks on map" feature is on everyone's enhancement list, but with the above workaround it's not a big deal.
2012 UT/ID/OR 2300mi 11d Outback Ride via UTBDR, T2, OBDR