Hmm, nice to read that you are making progress fixing your problems.
But one thing pops into my mind here:
You are trying to make the explorers cope with a malfunctioning universe. I think it makes more sense to fix the real problem and leave the explorers alone. They have sufficient checks assuming that the universe itself works (every gate leads to an existing sector).
About the delivery script: I'm quite sure, that this will get signed. Simply because it still is in vanilla (signed) condition except from some changes I made.
Actually, even the vanilla delivery script is already a modified version from my very first improvement. I created the delivery.go script and made it run on the delivery ship. Before, all scripts were running on the trader which led to problems if the trader was stopped while receiving a delivery. The delivery ship would simply stop working and float around idling.
I'm still a bit disappointed, that I wasn't mentioned in those scripts...
Back to topic:
I'll take a look on your modifications. Maybe some of them also make sense in a functioning universe. But I don't want to fix other peoples bugs by creating workarounds in my scripts. E.g. checking if a gate leads to null is useless simply because a gate leading to null is a fault in itself.
So this is work that doesn't need to be done.
Btw, I think it isn't only a gate leading to null. Maybe even all gates work correctly. I rather think, it's got to do with jumping itself. Because delivery ships are created in a valid sector, the sector of the sellstation. They THEN jump into the customer ship's sector and that's where they end up in null. The customer's sector does exist, though. The customer is waiting in it. So something with the jumping procedure might be wrong...? Maybe that helps your investigations?
I have not been able to get Mk3's to restart on their own. I expected that incrementing the version number would restart them, but it does not appear to do so.
It does, but the check happens only once per complete trade run.
My schedule says that I'll be back home this evening btw. I'm at university right now. I'll take a close look on this stuff then!