How long a trip, and in any remote areas?
For normal close to home, not much is needed and the basic tools are fine. I carry a shock key, gap gauge, 10, 14, 17mm combo wrenches, a crescent wrench, the Honda screwdriver kit (flat handle and 3 drivers), hammer impact driver and its tips, plug wrench, slipjoint pliers (smallish, from some old Toyota tool kit), small tire gauge, and probably other little tools that all fit in the underseat case (400F). And as I have an oil pressure gauge fed from the right gallery plug I carry a 1/8 NPT plug in case the tubing to the gauge breaks. And Allen keys for that plug and various engine screws I've swapped to SS Allen ones. And spare fuses, both sizes. It all fits in the case (no roll). Plus I have a signal bulb in a 35mm Kodak film can (remember those?) taped to a frame tube. Tail/stop bulb is a LED that shouldn't burn out (hope!). Tools in the tray have to be placed just so to fit, that impact handle is large but I think it's maybe the most important tool to have.
I have pods (no hate!) so I've capped the filter box hole and have a spare H4 35/35 bulb, small chain breaker, a few links and half link, 4 plugs in a candy tin they just fit in, a foot or two of duct tape rolled up, the owners manual with papers tucked into it in a ziplock bag, some bandaids and alcohol wipes, probably more odd crap in there.
Longer trips (rare for me now at 71!) I take a bicycle pump, tube patch kit, tire valve wrench and spare Schrader core, 2 sweet little tire irons I forget the brand of, a few bungies. All in a small "purse" bungied to the back of the seat.
Yes the 35/35 bulb isn't very bright but my battery actually will fully charge from an hour or so on the highway.
Yes filling a tire with a hand pump is slow and tiring but usually it only needs to be pressure enough get me slowly to the nearest place with air. Flats are pretty rare so it isn't much of an issue.
If you've never had a flat, it feels super weird but will never be forgotten. Like you're sinking into quicksand amd weaving in an odd uncontrollable way.
I have never used a boost pack but not a bad idea. How often could it be useful though?