David.... That's a good point. The UK has part A and part B contributions as part of income tax. One part is specifically for your pension, which you receive when you retire anywhere in the world regardless of your wealth. Australia doesn't have this system. Income tax paid in Australia goes into general revenue and there's no specific connection with your superannuation balance. So, if I earn 100k in the UK my pension balance will be larger than a person that earns 50k. Not the same in Australia. In Australia income tax has almost nothing to do with super. The gvmt wants people to be self funded, and use the super guarantee levy of 9.5% for that, which is on top of income tax, but levied on the employer.
I couldn't see it mentioned previously. Along with a time in Australia test, there's also an assets test. I think the primary residence is excluded, but self funded super balance, shares, term deposits, investment property, etc, are included. Some one on here will know more about this.
, it seems there's no requirement to renew covid cover once you're in Thailand because it's currently not a condition of the OA visa extension. You'll need the covid cover only for your CoE. But, something off topic for you to consider. When you get back to Australia, you will need Australian Border Force approval to depart the country. Although you normally reside in Thailand, they're particularly tough at the moment. They've been rejecting people that have wives, businesses, property, etc, in Thailand. And then there's the current arrival caps. I'm sure you'll have no difficulty, but thought it worth flagging these issues.