I need to install slow motion switch machines for a yard that is directly over staging tracks, so the clearance is fairly snug. I prefer a directly-under-the-turnout application, (which in this case, rules out Tortoise). The desired specs are:
slo-motion (not interested in solenoid devices),
needs to be 1.5" or less in height.
needs to have maintenance-free SPDT capability for frog polarity (don’t want to use the points-against-stock rails for the electrical contact).
Circuitron makes remote mounts for the Tortoise machines that lets you mount them on their side, at a pretty good distance from the actual turnout. So you could use the remote to put the machines between your staging tracks where they won’t interfere with the trains.