Maybe you misunderstood my question. I want to purchase BTC ETF shares equivalent in value to an amount of BTC that I would send them from my private wallet, without selling my private wallet BTC first (thereby creating a taxable event). I would still be the owner (so no tax event) but the ETF issuer would now be the custodian.
You cannot do that, because ETFs are based on trusting them to buy Bitcoin, and you do not have experience or trust that you can keep Bitcoin safely, so you need to sell your bitcoin first but why do you do that? Bitcoin can be an investment and you can use it as money to pay, while ETFs are stocks.
If the sale makes you a profit, it is subject to tax, so wait until the price of Bitcoin rises, sell it and buy shares when the price falls again.
This is not tax advice, you should check it yourself.