Operating characteristics should not be an issue with 3rd Rail. I have a 4% grade that my engines are able to climb quite well pulling 15 cars or more. The same for passenger cars. I use Atlas tracks and turnouts--no problems with the big Pennsy 3rd Rail steamers:N1,Q1,Q2,J1a,T1,etc. I have an O-63 reverse and an O-63 curve on a trestle. All other curves are O-72 or greater--no problems.
I look forward to the new L1.
Norm Rish