As it was already stated in @misc,
I don't think I got that message. (?)
mtier is probably as safe as relying on openbsd code.
I'm not worried so much about safety in the sense of compromised code, but rather the practicalities of setting up a workflow that depends on something that can disappear at any time without notice. Their website has zero information about them as a company or who (if any) of them are also OpenBSD devs or what. It also looks like they only started a couple years ago.
