I don’t know what kind of advice your strata manager is giving you but the new laws on short-term letting haven’t come in yet so I can’t see how they can base their advice on results issued by NCAT under the old laws.
The old (curent) laws depend on the part of strata law that says you can’t interfere with the buying sell of leasing of a lot. That is interpreted as meaning you can’ prvent people from doing what they want with their property, in terms of leasing it.
Most strata lawyers whom I know say that, under current legislation, if you have a DA that says no holiday letting and you pass a by-law saying you support your council DA, then that is perfectly legal.
The thinking is that, as the owner never had the right to have short-term letting to begin with, you are not interfering with nayone’s rights by imposing a by-law that says you are going to ensure owners abide by the law.
It’s when you start allowing holiday letting with conditions that you are in breach of strata law, because you are then giving the owner the right to breach your planning regs, and then trying to control it.
I think your strata manager has given you really bad advice and I would seek a second opinion from an experienced strata lawyer before you register the new by-law (which I think may be in breach of strata law anyway, and therefore invalid).