When is this plugin gonna get updated? there so many missing items like electricity items, Boxes, gun attachments, etc

Mine are all there? Pointless having the electrical items listed anyway, server will always auto-set them to 1.

"[Stack Size Controller] WARNING: Item 'AND Switch' will not stack more than 1 in
game because it has durabililty (FACEPUNCH OVERRIDE). Changing stack size to 1."

All the new electrical components have durability.

electrical items i can deal without but there few i can't find on my list like doors, large boxes, and few gun attachments which i really wanna change 

So, add them in? It's not hard :)

Do people still use this plugin? Does it even still work? Is CanopySheep active anymore?

I dont know what version  you are using but mine is up to date with all the new items . If they are not there just add them but you have to realise that any "new" items will not stack over the default 1, some diving parts will stack more than one but most dont, you just have to experiment and put the number you want there, if its ok it will stay if not you will get the durability notice and it will stack it at default size, its a great plugin without many problems

AND guys if you didnt notice its a holiday time so people with families and friends IRL are not regarding this with the importance you think it merits, relax and work it out.

I only asked because I developed the plugin back in the day, if it's not being actively updated then I thought I might take a look at it.

I think a lot of servers still use this plugin or unless they're using a different one

I still use it, it's great.