Living on margin
I was a user of collateralized credit for a long time before I built any. For years I ran a margin loan on Robinhood and used it the way most people use a checking account. It was how I spent, and the positions behind it stayed where they were.
That is a normal thing to do if you know what a maintenance requirement is and you keep an eye on it, and a very bad thing to do if you do not. The margin desk does not call you, it just sells.
Gether is the version of that I wanted to exist. Same idea, spend against what you hold, but built as a card with underwriting and liquidation logic that is designed for spending rather than for a brokerage. I use it now instead.