Homosexual marriage is not marriage at all, so these two things can’t be conflated as you’ve done.
Please sustain your claim about gotquestions position, I don’t think that they are making the claim of perpetual adultery as you allege or think they are.
Read
this and
this, because not all conservative Christians believe that the solution to an adulterous remarriage is to compound that sin/mistake by adding to it.
I’ve never addressed gay marriage, other than in passing, and I’ve never preached on divorce, again, other than in passing. As far as your comments elsewhere in this thread about the reason for not preaching against it as a perpetual sin, I’ve addressed that (it’s not necessarily), but if I believed it to be something that the church was indeed guilty of, and I would preach what the remedy in the gospel would be, regardless of financial ramifications.