Used to want gears too, now I get it.

Learning this the hard way too, my old Netgear switch sat on 2019 firmware until last month lol. What actually worked for me was just making a recurring calendar reminder every 3 months to log into each device and hit the check button manually. Sounds dumb but it takes like 10 minutes total and I actually do it now. For the ones that matter most (router, NAS) I set up email alerts through the admin panel so it pings me when new firmware drops. The rest of the old junk just gets a yearly look during spring cleaning. Auto update is great until it bricks something, so I keep that off for anything I can't easily reset.

Paying $4,100 hurts but you did the right thing. Here is where I see it different though. Most people wait until the fight starts, then no lawyer can fix it cheap. The papers only help if you sign them while everyone still likes each other. After the split, the other guy has zero reason to sign anything fair. So the real win was writing that check before the next partner came along, not after.