Mark,
Good idea on the testing methodology and likewise, the advice on transition also makes a lot of sense. Common sense applies. I can recall as a kid being able to pull my three passenger cars with a magnetraction Hudson up a steep grade of Lionel trestle since I had to do so in a short distance - I believe it was probably a 4x10 or so layout. I also did so with a short freight. But I do remember it wouldn’t work if there were curves involved or if I began adding more cars. The takeaways from that is it depends on what you want to accomplish. So using your advice, include curves and a typical consist in the testing, and if it works, you’re set! If you have plans for something more, then think twice?
Bob