In reply to Liber vs. Floris:
It’s not acceptable for a first release.
Once you’ve established a reputation with some genuinely “non-inspired” typeface designs, then it’s OK to publish stuff that’s quite similar to someone else’s work. Myriad/Frutiger and Gotham/Proxima are well-known examples of this double standard.
(The above is not my position, just an observation of the status quo.)
And of course, plagiarizing oneself—no problem!
