Additional note: “the other odd thing is that if you exceed the cap, I believe you can ask the tax office to release the amounts that exceed the cap such that they become regular income “

Looking into the release for amounts above the cap, you can release up to 85%, but it must be in order to cover tax liabilities.

This explainer is relatively good: https://www.heffron.com.au/knowledge-centre/what-happens-if-you-exceed-the-contributions-limits