Sometime tomorrow I will be taking over the hosting of bantflags from 4903000.
You should be able to continue using the userscript unaffected, however there may be some issues I haven't encountered myself.
I have completely reworked the userscript, with some sizable improvements, including using up to 30 flags at once, vastly improved load times and auto updates. Please do note that you now have to click the 'load flags' button before you can add new flags to your selection.
Again, you shouldn't need to upgrade - all versions of bantflags will be supported now and forever - but you can download the new script from here:
https://flags.plum.moe/bantflags.user.jsCurrently only newly posted flags will show up on 4chan and Nyafuu, since I don't have the old database, though 4903000 did say they would upload it sometime so they may show up eventually.
Of course, this means that I will now hold all of the data collected by bantflags. This includes the post numbers and flags selected of all posts you make on /bant/ with the userscript enabled. The new script also sends a version number, however this is discarded and not stored in the database.
bantflags is free software, the source for which can be downloaded here:
https://github.com/C-xC-c/BantFlags/ 