I found a way, a bit clunky.
In route planner create a new route, then from the menu add the route and track needed, then they can be compared.
Or, show the route on the map, then under tracks open the track you need.
I do find MRA unnecessarily complicated.
I have never tried this, so just did:
1. Opened a route
2. Saved a GPX of the track
3. Imported the track to the Track Logs in MRA Planner
4. Open Route in Planner
5. Left Menu and selected display tracks
6. Added the track created by exporting the route.
As I use a Garmin, I have a different method which is:
1. Create Route
2. Send to Garmin
3. Set Garmin to Display Track
4. Open Route in Garmin
5. Scroll around the ma and ensure route and track match
6. Edit route to add via points if they deviate and go back to step 2
An observation I have made over time is that MRA route planner routes using the "Here" engine is very accurately followed by the MRA navigation app (as one would expect / hope) but less so with a Garmin XT which using the above method exposes the differences.
If going on a trip in a group with different people using different devices I would use the MRA ROute planner "compare" feature to see where any route deviates between the 3 calculation engines:
This adds another option to try and minimize any descrepencies with bikermates;
I am looking at the MRA route planned with "Here" maps, the imported track and a comparison with Here and Tom Tom, the reason for this deviation is that "Here" maps refuses to go along that bit of road with waypoint 10 - it has done for years, you can add as many shape points as you like, turn off seasonal closures, but here inists it is not passable.
A bit of effort to get the track showing, worth asking MRA support, they might say they will always match so it is pointless???
I will run some more tests on some of my longer routes now and see if I can find any differences, although I may need to start remving shape points as most my routes have gone through this comparison to iron out any differences from Here <> Tom Tom <>OSM already.
Final point - most modern navigation devices / apps are capable of using "live" traffic and road closure info, so despite all of this you may find on the day things change a bit, here is an example I found recently
A quick google gave details of major roadworks, Here maps is aware and routes around it, Tom Tom (Red) and OSM do not show it in the maps, maybe on the day they would? Maybe they would just drive you right up to the blocked road?