I know my influence on amendments tends to be low and I'm the leader of the unity option, but I'd really like to see either a 50% turnout threshold or a requirement of more than a simple majority for the referendum to pass. This is a big decision, and I think that it really needs a clear mandate if it passes. (Also, there is the precedent of the original bill having one.)
That's not currently required for constitutional amendments to pass. You'd have to amend the constitution to make that threshold possible. I'm not sure that it can be done in one step - though I suppose if this amendment said that a 50% turnout threshold was required for this amendment to pass, it might work.