Installing an additional browser plugin is not state of the art, if possible move this functionality to the network filter level of your products.
Addional browser plugins may stay available for non F-Secure customers as an additional information source.
Sorry for my potential feedback (I'm also only F-Secure user).
But my own feelings is that:
-- main protection functionality already work with suitable level.
-- browser addons/plugins/extensions as F-Secure Browsing Protection addon about extending abilities to handling (safely) secure protocols like HTTPS.
For example, to show 'rating' pictures with search results under HTTPS searchpage; to properly detect/block harmful or banking rated websites under HTTPS; maybe some other tweaks.
But all abilities like block access to harmful-rated page (or so) does not based on addon/extension.