I took the view when I started building kits that I had to spread my gear out for multi use until I had enough to build separate kits.
I started building modules. I use containers like Pelican Micro Cases and Otterbox, and some nylon pouches etc.
I have everything labeled, and its all ready to go. I have a small pack with a number of containers ready to zip up and go as my BOB.
I have a couple of other sized packs near by and if I am doing an activity I sellect the containers I need to suit the activity.
I do have redundancy and size range covered. For example I have 3 different battery containers ready, all different sizes holding a different amount of batteries depending what I need for an activity.
If I need to get out of there fast the lot gets dumped into the back of the car or just the prepared BOB goes with me depending what the situation allows.

Ive actually got enough to build more kits, but Ive used it to add flexability and redundancy into what Ive already got.