re: Using HSA withdrawals to fund Roth IRA

That's actually really smart.

As long as your HSA is over $2K (I assume it is much higher than that but it doesn't matter), then this is a great move.

You've incurred $2K in qualifying medical bills. So the two choices you've considered are moving the $2K into a Roth or keep it in your HSA.

Both grow tax free, except in the HSA any growth is only tax free if its used for qualifying medical expenses. So the same $2K moved over to a Roth will incur growth that is tax free no matter what it's used for.

So you have more flexibility with your $2K moved to the Roth.