Great ideas but the performance hit, as others report, is too severe. Disabling other addons does not seem to help. (Firefox 133.0.3)

Severe performance impact. This extension significantly reduced responsiveness of the YouTube subscriptions page. Channel group management page was very choppy. Actions taking at least 5 seconds to complete.
Update-disabling add-ons did not improve performance. I have over 700 subscriptions, maybe that is too many for the extension.

yeah it works, but why does it hide certain videos from the all subscription feed?? How many videos did I miss bc of this strange behaviour?? only hide when I click a certain group. Then you can show all (new) vids from the channels in the group and hide the rest. But when I go to youtube / feed / subscriptions and don't click any group or whatever then I wanna see ALL new videos, don't hide a.n.y.t.h.i.n.g.!!!

Screenshots showing what I mean I shared here: https://drive.google.com/drive/folders/1_T6yP0Kd2IwO4Z3xVrsnFeKJhVRfBVQ6?usp=sharing

Also, and these are less important issues that I previously posted, why is the 'adding channels to a group'-process restricted to a small paged popup window? Do you really think I started watching youtube just yesterday? that I started subscribing to channels just a moment ago? I've been watching youtube vids since YT's first creation and am subscribed to hundreds of channels. You want me to sort through that in a miniscule frame? gimme a browserwindow-large sorting window with infinite scroll at least so I can have a good overview. It's bad enough already that I can only see each channel's icon+name/handle (which most times isn't very informative about the channel's content), but at least give me a c.l.e.a.r . w.i.d.e . o.p.e.n overview to ease my sorting

And another suggestion, in this 'select channels to add to group' window, label each channel with tags to which groups they're added to already. eg when I add a channel to the group 'tutorial' and am then later in the selection window for adding channels to 'art' then show a 'tutorial' tag behind the channels that I added to the tutorial group earlier. That way I can have a bit more info on the channel than only it's icon+name already! Plus then I have a direct view on which channels are yet not grouped in any of my groups

This extension is very laggy and clunky to use. It's such a great feature that mildly pisses you off due to how slow it is to load anything. Not to mention the random days where I have to refresh youtube multiple times with multiple tricks to make the extension features actually show up. It's in dire need of heavy optimization work. Great idea limited by the execution.

Most needed functions are paywalled. Some are not (hence the second star). Seems too bloated If you just want to use the free options -- frequently you stumble upon something that only works when you pay money.
Would use a clone of this with just the free options -- it probably would deserve at least 4 stars.

The `watched` status is not handled properly, and in two ways.

On the subscriptions page, it seems like the Hide Watched checkbox needs to be re-applied for the filter to work, the Play All button here does not work.

In a Channel Group page, the Watched tab doesn't remove watched videos from the list.

Header in subscription list (that permits to turn on and off each category) works in Chrome, not in Firefox...

How do I restore the grid view to the subscriptions page? Not even disabling or removing the add-on did it. :(
Edit: the grid/list options now suddenly appeared after I refreshed the page once more. :/

It doesn't work on firefox. Console spams "Uncaught (in promise) Error: Could not establish connection. Receiving end does not exist.
updatePopupStats moz-extension://76eca0c8-522f-405e-81d8-feae8afbc3c4/lib/ui-service.js:231
ui-service.js:231:25"

Грузит процессор на 30 %, после отключения все норм.

used to work but now it doesn't even show up on my you tube i installed a older version specifically 8.014 that version seems to work but none of the newer ones work
it has three Warnings listed

Reading manifest: Warning processing options_page: An unexpected property was found in the WebExtension manifest.
Warning details

Reading manifest: Warning processing oauth2: An unexpected property was found in the WebExtension manifest.
Warning details

Reading manifest: Warning processing key: An unexpected property was found in the WebExtension manifest.

the console also shows this error
Uncaught (in promise) Error: Could not establish connection. Receiving end does not exist.

extension no longer works

После обновления оно перестало работать.

Love the add in but all of a sudden I can't add new sites to subscription groups in Firefox. I am able to add the groups in Chrome though. Any ideas?

Update 7/8/18:
On 6/13 I sent the developer a couple of screenshots because he requested them in a private email he sent me on 6/11. I am assuming that he received the email. I have not heard anything further from the developer regarding the issue I presented. I am still hopeful that there is a resolution to my problem. I have removed another star from my review, I will be glad to give 5 stars once the issue I am experiencing is resolved.

Update 7/25/18:
Since I still haven't received a response from the developer I uninstalled the add=on and then reinstalled it. This did not correct the original issue. I noticed that even though I uninstalled the add-on the subscription groups I created were still present after I reinstalled it. I wonder if there may be a limitation to how many subscription groups or subscriptions you can have in Firefox. As I originally stated I do not have this issue in Chrome.

Used to work great, now I get errors from Firefox that this script in particular is slowing down the page. I have to temporarily disable it to watch a video or even get a channel's homepage to YouTube to load. It even does this if I have the side panel closed. I have 564 subscriptions and I am using a 64-bit version of Firefox on Windows 10 Professional. Not sure what's going on beyond that. Very sad, though.