That's a pretty common investing strategy. Take a HELOC, invest the money in index funds or whatever, and take a tax write-off for the interest. As long as the average return beats the HELOC rate (minus tax deductions) you come out ahead.

Someone noted it as an investment strategy (which is one way), but I was specifically using it to address the ‘you don’t get the money until you sell’ element.

You pull money out of the HELOC, which does give you access to the equity. You then pay it down similar to a mortgage, at very low rates.

You just cashed out some of the ‘inaccessible’ equity by using it as loan collateral.

You’d still get to live there, and any gains in equity will be 100% yours. But you have cash now, with low payments and low interest to pay it back. If you do sell, proceeds could go right into paying it off.

There are similar ways to setup second mortgages, etc.