I think I didn't understand your reason for converting Bitcoin to fiat currencies or stablecoins.
Why don't you keep Bitcoin in safe wallets and convert them when needed? That way you won't miss out on the increase in Bitcoin value?!
I have solutions for you, of course, I don't know if these are taxed where you are and if they are, is it enough for you to save money or not!?
1. There are places where you can invest in them, such as gold reserves and use their profits to make compound interest.
2. Convert to precious metals and store them in a reliable and safe safe deposit box that you know.
3. Buy valuables and antiques. (It should mostly look like they are for consumption and not an investment reserve for the future, because if so, it will probably be taxed).
As I said, you should consider these options depending on where you live and the laws that apply to each. In my opinion, these options can help you get the most out of your money.
In addition, security is never 100%, but you can minimize the damage by reviewing and choosing safe items or damage protection.