I don't really like having to use my mouse to select a Kagi lens to filter my results. I think it would be very convenient to be able to use a search operator or bang to have the results of the query be filtered when the results page is presented.
Using a search operator or bang for a Kagi lens it could be something like:
lens-programming: C++ keywords
or
lp! C++ keywords
the specific search operator/bang could be user assigned in the lens setting.
This way a lens could be utilized directly in a search bar instead of having to wait for the results page to load and then selecting a particular lens with a mouse. I prefer to use the mouse as little as possible.
