Perhaps Termius is a fighting a bit much against the flow of "terminal"? FWIW terminus is also a word frequently used on transit ("Terminus station"), which is kind of cute.
Is the problem that it's an existing trademark, or just that it's annoying to change again?
It probably doesn't matter if I misread it, search engines will take care of it as if a typo? (Same applies to anyone accurately searching for the name I misleading recommend them, too.)
But, perhaps you could do something with the capitalization of the name to make it more obvious:
"termiUS"
You could accentuate that effect with using a larger font for the last two letters.
Seems like one of the benefits is synchronization, so emphasizing US fits. And then you don't lose your hard fought Google ranking.
But, in any case, it's a great product and good luck!
Human brains are proven to error correct misspellings on the fly, and you are getting told by everyone your name is error corrected to something you’re saying it’s not. That’s a big deal.