About the kit, no way you're gonna find a multi-tool that has all you need, so it will just end up being another tool added plus more weight. And they are bulky and not eaay to use for precision work like building vape decks. That UD Cool Kit is as chunky as all other multitools. Since you like your scissors, you'll never settle for using those tiny scissors in a multi-tool. They are only really meant to use in a pinch.
You're best bet is to downsize and consolidate a few things, namely your cutters and your screwdrivers and hex drivers.
Cutters: I personally never used both diagonal cutters and nail clippers, I only ever needed one or the other. Perhaps try to make due with one, not both? If you use nail clippers cuz your diags don't cut well in certain cases, either shapen them with a small, fine file or get a better one.
Screwdrivers: If you buy one of the aluminum pocket screw drivers with the magnetic end where you can change out bits, and store them inside the handle, you can replaced your screwdrivers and hex drivers with one tool.
This one comes with hex bits (0.7mm, 0.9mm, 1.3mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm & 4.0mm). Comes with a case but you just store whatever bits you need inside the handle and not use the case or the rest of the bits. I have one of these, just a different brand but same design. Mine is 4.5 inches long without a bit installed.