I have used the ST1413ST1413 Woodland Scenics 4% x 2' Incline Starter 1" Elevation (x4/Set) on my layout. The Bachmann Baldwin and Double Fairlie can handle it with no problem.
Yes they are a bit expensive but I only use them on the coach / wagon next to the loco. I tend to keep my coaches / wagons permanently coupled together with the Peco short couplings. With a magnet under the track I can uncouple very easily. I have tried the Greenwich couplings but find them very tricky to assemble.
Sometimes you just have to bite the bullet 😀😀