I started conforming to the rule 'Whatever belongs to the bike, stays on the bike. Whatever belongs to the human, is carried by the rider'.
Now, each of my two Specialized e-bikes (Vado and Vado SL) has its own:
- Topeak Mountain Twin Turbo Gauge pump installed on the frame
- A spare SL Range Extender in the water-bottle-cage (Vado SL)
- A saddle bag with these items:
- Two spare inner tubes matching the wheel/tyre size
- Tools and small parts:
- Tyre levers
- A multitool or a hex wrench set
- A chain tool
- A set of nicely wrapped chain quick links
- The tools are stored either in a pouch or a small plastic bag (wrapped in a bubble wrap)
It has happened not once and not twice I was on a relatively short ride and caught a flat. I wouldn't like to do the "walk of shame" again

Regarding the human needs, I either:
- Take my Camelbak hydration backpack for longer rides, or
- Carry a small but spacious backpack for shorter rides (the water bottle inside).
Now, the rear racks (either permanent or removable) only serve the needs of grocery shopping. Or, I use a pannier to carry the spare battery on my big Vado.
I share my Wahoo Roam 2 between both e-bikes (a tad too expensive to own two of them!)
You might correctly say I've overdone it

Not really. It happened to me (for several times) either of my e-bikes was unusable (for example, a flat detected at the last moment, or something else). I must be in the position to grab any available e-bike and ride out without moving the equipment from the other one! That's also why my e-bike batteries are always being charged post ride as well as Wahoo and anything electrical, and I pay attention to inflated tyres and well maintained chain