ya probably for big users. I only have 4 phones or will right now. Also just had the zero laying around worth the test. I wont hold it against 3cx if it fails LOL, I have a few Pi's on order now just in caseI guess a RPi zero W is not powerful enough to act as SBC, use the RPi 4B instead... that one is recommended.
Founded in 2005, when VoIP was an emerging technology, 3CX has gone on to establish itself as a global leader in business communications.