Okay, I’m ready to announce another major version. This version of the extension has a fully enabled Bulk Action mode that allows 30 (or if you increase the per page limit, up to 200) actions to be applied at a time. I’ve also made some bug fixes, minor UI changes, and two major feature additions: you can group buttons into sets and swap between them on the fly, and you can create custom lists and add observations to them to revisit later. So for instance you can make an action that adds observations to a high-level taxon and also adds them to an internal list (saved on your browser, within the extension) to revisit later, then use the URL generator to search within one or more lists at a time.
I haven’t received any feedback in a while so please let me know if you run into issues, or if you use it a lot and it works smoothly. Once I get some clear indication that it’s bug free, and that the iNat staff is okay with it as it stands, I’ll publish it officially on the browser extension stores.
Download it here and then follow the same installation instructions as in the OP.