As the subj says. What's more interesting: sometimes it kills neutral NPCs, like chickens, sheep, and sometimes it explodes upon skeleton impact.

How come it kills on low speed and is unable to kill on high speed? This sounds pretty ridiculous.

Well I don't disagree on that. Not sure why its happening like that. Race condition possibly I suppose.

I just want to figure out what to do with my current rails setup - leave as is, remove HS, wait for fix; Or just remove it all away and make a new one?

Is there any possible estimate for a fix? Like, a week or two or etc.?

Sorry, no. I might be able get a fix into the beta versions that fast, but not into an official release. If you are interested in becoming a beta tester, see my Patreon page.

OK then, seems like making a HS locomotive road basically makes no sense right now… :/

Or, you know, put fences around it or raise it up to keep mobs off.

No reason to give up just because it wont fix itself.

Well I did, but spiders are able to crawl over and chickens somehow slip through here and there, especially near tunnel entrances.
Looks like I'll have to go for a monorail up in the sky then... Will need load of crushed obsidian for that.

make proper fence structures and the spiders n chickens can't get in.

Make a fence cage? Thanks, but no. I'd prefer slower but scenic ride, rather than ride-in-a-cage.

I made some tweaks that might help for next update. No promises though, I didn't really test it.