I was wondering if there is a way to further invest with my BTC and other cryptos without and being in legal terms. As in ways that would not be considered a taxable event.
You can invest in bitcoin on a non custodial wallet, hold it for years and you will earn from it without paying anyone tax to either maintain the wallet you're using or the unit of account for your asset value as the banks do charges for maintenance.
I know crypto to fiat and doing trades now is consider taxable.
Even staking?
If you're going to opt in for trades, then you are likely to make use of the centralized exchanges in doing that and there is no how you can manage to escaped being taxed from these exchanges, what you should considered is the rate you're being charged, which i think should be more affordable for you than not, except you're not going or make use of a centralized exchange for trade or avoid trading at all.