In SevTech I have made great use of backpacks -- an Improved Backpack in a bauble slot, an Iron Backpack in my inventory, and a Lurker Skin pouch from the Betweenlands (stored wherever those Betweenlands things go...). All 3 have been upgraded as much as possible for the age I was in, and all 3 have been accessible via a hotkey. All in all, this has been fantastic.
In age 5 I have finally unlocked all of Refined Storage, and I know from other playthroughs that a Portable Grid (with even just a 1k drive) makes for a huge backpack/toolbag. I have been spoiled by the hotkey access to the other backpacks, though, so I am now wondering if there is any way to access a Portable Grid via hotkey so I don't have to keep it in my hotbar all the time. I have not been able to find one, neither in-game nor by potentially adding another mod for that purpose.
(It would be a cherry on top if there is also some way to get it out of my inventory, such as wearing it as a bauble.)