FWIW:
Think of traction tires as the model equivalent of the real thing having sanders on permanently.' If the real thing was running on our grades I expect that would be the condition.
I suspect that if the driver rims are steel and the track is brass/nickel silver, running w/o traction tires *should* not cause significant wear.
On occasion when a traction tire has expired inconveniently (no replacement at hand) I've filled the groove with rubber sealant. Works, but you have to be careful not to leave lumps...ask me how I know.
I have a Lionel Reading T-1 sans tires. Runs fine with the sort of train I can run at our club. Requires a little throttle jockeying when starting, which adds to the fun.
