Sell real BTC to spot ETF, and take out collateral loan

Hi, I'm trying to figure out the safest way to take out a collateral loan against my BTC. I don't really trust any of the companies that offer it.

I was thinking of selling 15% of my HODL portfolio and buy a spot BTC ETF, and then get a collateral loan against it.

The pros I see is that the ETF is protected by SIPC

The con is that I would have to pay capital gains tax even though I'm just transferring the money from one form of BTC to another.

Please offer tips, critique, or suggestions?