Sleazy Fork is available in English.
Adds a few quality of life improvements on Sankaku Channel: Automatic image scaling, scrolling to image, thumbnail icons for loud/animated posts, muting/pausing videos, + - tag search buttons, a tag menu which allows for tagging by clicking, 'Choose/Set Parent' modes, easier duplicate tagging/flagging. Fully configurable through the Addon config.
First of all, sorry for the late reply.
Second of all, hm... I don't use the beta site at all and I don't think any of the scripts features could be transferred.
In other words, a whole new script would have to be written - and I definitely don't feel up for that.
I think the best course of action is to give your feedback/suggestions to the Channel Beta Feedback Thread or the Sankaku Complex Development Thread.
You could suggest a profile option which always loads the original image.
Actually, someone already did and Winter forwarded it!
Since the android app already does this, there's a good chance it'll be in the beta channel too.
[Suggestion]
I would like to know if this script could interact with the beta site and have the script load the original images instead of the compressed version.