I don't want to jinx myself; but tentative happy chirping from me.
Just got back from the Dealer in my freshly replaced brand new battery Kona, and sitting down with a cuppa and a scone.

Based on the month long initial diagnostic fuss, I was imagining a sordid and lengthy drawn out scenario, full of generic car dealer weaseling and hands up excuses. To their full credit, they loaned me a brand new less than 3,000 km courtesy car. (Elantra, which I discovered is almost 60 centimetres longer than the Kona, lol) Boy was I surprised to get the call this afternoon to come pick up my repaired car already!
No paperwork involved, they just handed me the keys, and I was on my way. I did enquire whether it was a new versus "refurbished" job, and for what it's worth, they swore it is brand new. Also I'm looking at it hopefully, that I can be spared a nasty surprise of the dreaded crystalized coolant clogging sludge up or whatever it is, based on the system getting a full flush and being replaced with new stuff, as an incidental bonus effect of the battery replacement.
Thanks to all for the commiserations. *knock on wood*