My $15 Raspberry Pi Zero W (2017 vintage) arrived yesterday. The short answer is it works with my software and can be used to control trains! The longer answer is it is v e r y v e r y s l o. w.
It takes very little power, with is a plus, but it is pretty slow to boot up. I'll post some pictures of it running my Lionel Strasburg switcher once my LCS Ser2 arrives (I've switched locales to Boston for a few months; I miss my layout in NH already.
-- Dave