First of all , thank you for this discovery (yes yes we learn every day :) )
I just did the test for the trouble and I succeeded in what you are trying to do:
So in your sketch you put your trajectory side, so far so good.
To make it display on the MEP side, I used Model Object and then activate the options that suit you.
After if you have a lot of dimensions on your part you can always change it to Unmarkedfor drawing, this is a simple way to filter the dimensions. (in the room, right click on the dimension / Mark for drawing unchecked, on the MEP side remember to disable the other options)
this is to be kept preciously! Moreover, I find this feature very badly done, even if I frequently use it to simulate crashes while SW doesn't know how to do it normally.
I hope that just for that Santa Claus will spoil you ;-)