Allow us to either customize our backpacks like adding armored bug plates or extra pouches that give us another line of storage or a backpack that auto deploys the dandelion seed after falling a certain height or one that can deploy a dust cloud once you get hit and then has a 1 minuet cool down or one that heals you if you're almost downed but then has like a 5 minuet cool down. you can have it be like finding different types of bags in the backyard similar to how the SCA.B flavor scheme works but for backpacks maybe even get creative with environmental story telling on how the backpack got there like maybe with the dandelion one it can be found snagged on a branch in the hedge but below you can see a human shaped hole in the mud below where the backpack is suppose to be both telling the player someone fell there and letting them know there is something up there. Also maybe give us control of the color of the backpack.  

I ve thought about something like this as well, great ideas!

Love this idea. I'd like to find a unique part for each function you listed and then need to use those as part of the upgrade.