This assumes that a fix is coming. So far we have one person who has identified upgraded chips being installed at the factory.
We have no idea what caused this to happen or if there is a plan to install more upgraded chips at all, let alone on all units going forward.
I think we have to assume, until we have evidence otherwise, that it is what it is and if you want to eliminate the hiss you have to do the Lysander fix at your own expense and the cost of voiding your warranty.
Given the large number of positive reviews and the low cost of the item I don't think it's unreasonable to give serious consideration to doing the fix on your own if you find the hiss objectionable. Anyone who already has one, is outside the return period like me, and plans to use it at home playing alone has the choice of living with the hiss or doing the fix.
Hoping that Fender is going to upgrade the parts going forward or in the future is a crapshoot. The question is, what makes sense in the real world today? Fix it or return it?