The collateral will cost you 4x the loan value, and you'll need to trust them to return it to you, which you should assume they won't in the event of a volatile price downturn. Your liquidation point will be around a 50% decline. It's not the time for that yet. Until then, I prefer to spend the bitcoin that needs to be spent, while leveraging a certain amount 2x. You need a 50% decline to be liquidated in this case. Not ideal, but I don't like the idea of handing over 1M sats for 250k sats until the credit products improve via backend regulation or smart contracting, and the confidence curve (volatility) of BTC flattens.