I don't think whether a system is widely or rarely used is the issue, although it may give one pause for thought. The issue is a) is the alternative to the existing system going to be better or worse (or much the same) and b) if better, is it sufficiently better to be worth the effort of requesting change.
IMO advantages claimed for the proposed AV system are debatable at least, and the best that can be said of it is that it doesn't tie in parties to the government system the same way as PR would; so is at least better than them.