Another problem I have with between the rails magnets is my Bachman Spectrum 0-6-0 has a metal plate under it and the poor littlle shunter gets stuck over the magnet unless its going fast. This doesn’t happen with an under the track magnets. I can’t comment on electromagnetic ones, as I don’t have one yet.
MR had an article on using drop down permanent magents on main lines to prevent accidental uncoupling. It used a hinge at one end and a lever to raise and lower the magnet .
I’ve also tried experimenting with those really strong little magnets under the tracks without any success so far. It seems the trip pin needs a gradual magnetic field to pull it to the side rather than a strong field at the rails. (did I explain that clearly?)
regards
After experimenting with a variety of magnets, I’ve decided to go with the under-the-ties permanent magnet on a hinge for through tracks, and the smaller between-the-rails type on a few sidings. I’m using those long-tailed barn hinges, and bending the end of the tail down to provide an attaching point with suitable leverage for a pull cord.
The Micro-Trains undertrack magnets work just fine on Kadee HO couplers, so that’s what I’m using for my under-the-track dropdowns. The steel hinge has the same effect as the steel plate that comes with the magnet.