For street running tram lines the wiki suggests the usual way is to have the two ways (tagged railway and highway) share the same nodes, thus overlapping each other.
I didn't do that initially since I've read elsewhere that makes editing in some editors difficult, but let's leave that aside for now.
If we do that, does it make sense to add two separate tracks, one for each direction, on top of each other? What purpose would that accomplish?

Hi,

My goal was first to correct that section of Yanko Sakazov blvd - it was two separate lanes, which is wrong (it is one two-way street with embedded tram tracks in the middle).
Then there is the question what to do with the tram tracks. There is the option to leave both of them, but having them on both sides of the road when in reality they are embedded in the center feels wrong. Also, to connect, e.g. any of the foot paths to the street, they will need to intersect one of the tracks, which is also wrong. This could be remedied by adding sidewalks separate from the streets, outside the tram tracks, but that would require still more work and maintenance.
Considering that both tracks are running together in that section, I eventually decided to merge them into one two-way line.
What are your thoughts?