Good question about the ign wire ... I definitely did not connect it to an ignition source ... but I can't remember if I left it disconnected or if I grounded it. I understand the safety concerns but seemed silly not to be able to run the system with the engine/alternator running
My plan has always been to get a latching relay to completely cut all power from the jack pump system when not in use ... I like doing that because that basically eliminates any parasitic loss that can drain a battery over time. But since it's already been a couple years and I haven't done it, obviously it's been very low on my list of project priorities
This is what I would get:
https://www.amazon.com/gp/product/B072N8NYN2
(I already have one on my inverter circuit and works very similar to what disconnects the house batteries with the factory setup).