ssh to non-existent .local name never times out
Rather than make a bunch of comments, here’s how I would start to corner this. I can’t reproduce this yes, so I might be totally wrong. 

First, does ssh using a known bad local IP address time out fast or understandably / reliably?

Second, does the potential (or any) machine show as advertised?

 dns-sd -B _ssh._tcp local


Third, do you have any apple device that’s proxying bonjour sleep wake?

If not, why even try ssh to something that mdns could dig up later or have bonjour sleep proxy trying to keep waking that device. I could see how this longer time-out is by design to allow WOL via sleep proxy and multiple network segments to have a chance to wake your sleeping beautiful Mac.