Is there an option to seek legal advice from the Attorney-General on the validity of a by-law. If the A-G says a proposed by-law would be valid, then you could be more confident in proposing it to a general meeting to be adopted and more confident that a breach notice would be upheld by the Tribunal, especially if you provide the A-G advice.
An alternative to test the by-law after the adoption would be to arrange for someone to arrange a short term lease, perhaps even a committee member, for a breach notice to be issued and for that person to play devil’s advocate at the Tribunal. That could be quite openly presented as a test case, I would have thought.