Having seen that thread yesterday, I've just given it a fresh review, as a night's sleep might have helped.
But I still think it doesn't.
That thread seems to relate to variables set within the code. I really want to avoid changing the code we're downloading from our live web site, and just configure the local XAMPP setup to run with that. I have manage that already on 2 PCs and the current laptop (prior to reinstalling onto an encrypted volume yesterday).
So, I'm looking for a server-side fix, not web site code specific. Else, when we update the local/remote/non-www laptop, we'll have another tweak to do each time.
Off topic: In about an hour I've to re-install XAMPP on the laptop to what it was on Monday this week. I've achieved so much this week, it's ironic to be tripped up by something I've resolved before.