After these next couple of weeks I will be introducing a non-fixed end where people will only know the *hour* when it can finish randomly. No extensions.
Is this going to work, and not cause mass chaos and confusion? Not doubting you, genuine question, as history demonstrates... you know what you are doing!
A really simple modification to this would be to prevent new bidders from getting involved after the original auction end time. That would level things out a little more, and help reduce this nonsense.
Actually... a modification to your "non-fixed" end time, might be to make the "somewhere randomly in this hour" new bidders will no longer be accepted. Then, at that point in time, reveal the actual end time, leaving the auction extension rules in play as normal. If this wasn't enough, you could hide the end clock after the auctions had to extend 2 or 3 times. From then on, anyone still in the mix, causing the auction to extend, won't actually know how much time is left on the clock until someone either bids it up. Then when it all ends, reveal everything with the timings as well, to everyone that was actually participating in the auction.
Experiencing
@DomainOrder 's auction mechanics today for the first time, was actually quite refreshing. Setting aside everyone on here that was butt hurt because they were waiting for the last minute

... it was a "nicer" experience both winning and losing auctions (not sure how i'd quantify that though...). I now can't see the results of auctions I was watching, but not actively participating in (winning or losing), so the participants actions are shielded from history. I can see the results of auctions I was participating in, but not the bid audit history. This could leave room for abuse by the platform providers though? (not implying anything untoward about DomainOrder!)
I do wonder though... as I didn't know how many people were participating, did I behave differently? How did the psychology of that play out? On reflection, it was probably a
less stressful experience... but I need to give this one some more thought.