the only thing that would make this better is if you somehow found a way to get youtube to remember where in the sub box you are so when you reload the page it takes you right back to where you last were, i know this would likely be very hard to get to work but if you did, this would easily be the best add on ever made.

Edit what i mean is have the page remeber where you were so you don't have to stroll all the way back down to where you were since that can take awhile but as far as i'm aware this isn't possible due to how youtube works, the closest i think you can get to it would be copying the sub box to another page and have that page remember tho i'm not sure how hard it would be to do something like that