Gamesir T1 uses an XInput method as one of its control schemes, but does not seem to work in the XInput mode with Xbox layout enabled. Is there any particular reason it wouldn't be working if it emulates XInput controls? (Please note: This is not the T1S, as that is an entirely different and newer model than the controller I'm using.)
Videos are skipped when a container has an abnormal amount of videos per column. Like when all of the containers have, say, 4 items and another has 2: it will select a weird one.
When a video is too far down / up, it won't actually switch to it. Maybe implement a searching mechanic that finds the closest video on screen ( if there is one ).
Should scan like this:
Go down x amount of pixels, check, go left ( until you find a video or the edge of the screen is reached ), then if none is found go right. Go down, rinse, and repeat. Do the same thing for when going left to right, only searching upwards first, then going downwards.
For the youtube main menu there are sometimes little arrow buttons that you press and it displays more videos (usually under a channel). When going to the left or right if there is an arrow button, simulate a click on the arrow button.
I know you want the extension to be Open Source but, since it does not have a license, using it as an open source project is tricky. Would you mind adding a license to the repository?
A very simple license that you could use is the 3-clause BSD license that is used by Chromium, for instance.
Various button mappings such as the click map have stopped functioning at some point; I have been unsuccessful in attempting to make them work. Looking at the support tab in the Chrome store, this appears to be a widespread and longstanding issue with the extension. Scrolling and movement using the controller sticks still works, so I doubt this is an issue regarding the connection between the gamepad and the browser.
If you keep going from different video to different video and back to home a lot, eventually the sidebar will not be useable anymore. Either has to do with caching or can be fixed much like how #16 was fixed (using a validity check for the selected item). Maybe make the sidebar index-independent as well?
Add a way to magnify what the cursor is hovering over for users that are further away from their monitor.
Could be done similar to how iPhone does their selection mangifier. Or possibly a pop-up window that doesn't mess with the functionality of the controls.
If you're on a youtube watch page and the screen is really small, the text takes up more space than the video thumbnail and it thinks that there are more than 1 video thumbnail per row so it skips a bunch of videos.