I have been trying to follow the steps explained in Expanded extension support in Firefox for Android Nightly. I have succeeded in completing all the steps. Also, it really appears to work. After restarting Nightly, the Add-on settings no longer show all the recommended add-ons, but only the ones I have added to my Collection.
However, I cannot add any “general” add-on to my Collection. The search will still only find the recommended add-ons. Add-ons like SingleFile do not show up on the search field when I am editing my Collection. They do not show up in the search on addons.mozilla.org either.
Is there some step I have missed? Or has the procedure outlined in Expanded extension support in Firefox for Android Nightly stopped working? Also, is there a way to comment on that blog post? I would have commented there, but I did not find any way to comment on the mozilla blog.