Hey there, thanks for the review! :) I'm strongly inclined to believe that your duplicate imported engines were caused by a bug that I fixed in 3.6.0. Hopefully!

Could you please tell me more about the "open as link" icon not working? (or report the problem to https://github.com/CanisLupus/swift-selection-search/issues) It seems to be working for me, but sometimes the problem is hard to reproduce. An example would help a lot!

Exporting the preferences or even syncing with Firefox Sync is in my plans. ;)