great stuff!
the only thing different i can think of adding (and maybe this is my background in more "combat rock" situations with multiple strange bands) is that step one to me is rescuing all the mics first!
get 'em off the vocal stands, get 'em off the drums, just get them away from danger, from both theft and breakage while there are other people on stage stomping around packing their own gear and doing who knows what.
even if it means stashing them in a pile behind the amp rack until you've gathered them all, just get the expensive, fragile and easily pocketed stuff secured first. (these days i guess that means securing all the various tablets and laptops before even getting to the mics!)
Thats funny you say that - on single band gigs (my band) not an issue - but for the Jam I run/do sound at absolutely.
I am fortunate in that I have a couple of really good volunteer helpers, who do the heavy lifting, cable rolling, mic retrieval, etc.
I work on shutting down the computers, saving settings I want to (2 laptops sometimes a tablet), one guy sweeps for mics, another turns off speakers, while another gets stands, one or two work on cables, and by that time, I am helping take down speakers if there are any still up, and we are putting the entire system in the storage space. I use that Big Dewalt box for the cables, power, smalls, etc...... - and then we roll up the 300 lb 15x18 shag rug (we don't have a stage so....) and taking the drapes (moving blankets off of the windows (again this and the shag help sound wise in the room). If I have a gig, I take the XR18 (in rack) and my laptops. I have a bag of mic/speaker stands just for my band, cables and the smaller husky rolling box all loaded, and have some mics dedicated just for us. I also have separate K12s, Monitors, and a KW181 for the band. When Needed I merge some of this for bigger gigs, at the venue, or for my band, but for the most part, have worked hard to accumulate two separate systems.