I haven't done anything on this yet. As far as I'm concerned, it's yet another tool in the investor's tool box. It will work for some, not for others, depending on the situation.
I used to be all about minimizing debt. I paid off my credit card purchases every month, paid cash for cars, etc. Every once in a while, I would pay additional to lower our mortgage principal. When you have a diversified portfolio earning market returns (say 7-10%), the idea of using cash to pay down debt or pay for large purchases makes sense, even if the cost of capital is lower than your returns. The idea of borrowing against my stock would not have even crossed my mind.
BUT, as
@Artful Dodger and others have pointed out, if you expect (as I think most of us here do) TSLA to have much greater returns, using cheap debt to finance purchases/expenses may be the right call.