Greasy Fork is available in English.
To block groups on Mangadex's latest releases page
< 脚本 Mangadex Group Blocker 的反馈
I went back since Azuki Manga was spamming my feed and found a simpler solution than the time I wrote that comment so it's fixed for now.
MangaDex changed some stuff that made start and end of chapter elements to be inconsistent. I will not try to fix this since original language filter was added (also it's a pain) but will leave this up for future reference.