I had a little play around and it seems that if you use the 'built in change marker', you can choose the line type.
Some of the symbol line types (i.e. bubble) seem to be back to front when used with the change marker.
So yes, you would have to create a new line type that is reversed.
However, if you use the 'Basic change marker 25/26', then it should all be correct - it doesn't seem to use an actual line type at all.
This marker is in the default Graphisoft library.
One of the forum moderators.
Versions 6.5 to 25
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10