Yes, but at Hertz you don't have to "opt out"; it's simply that selecting a travel currency partners overrides any Hertz points earning on that rental.

And that's the way it used to work in the Avis Prime free weekend coupon era; you didn't have to "opt out" of anything, you just wouldn't earn toward free weekend coupons on rentals where you earned with travel currency partners.

So do you really have to "opt out" of points at Avis to get that FFP field to appear? I don't remember "opting out", but then I definitely never "opted in" to points either. And I've dropped from Preferred Plus (fka Avis First) to just Preferred, in case that makes any difference.