I've been receiving rewards from comments on posts with commentrewarder and I think it is a great feature here. I use Ecency so I don't know when someone is using it, but it would be great if they apply the icon here too.
I try to engage with people commenting on their posts but I know not much people do it and it could be a great incentive so people start doing it too.
Yes, it's necessary that the other front ends include the icon because it's a tool that could improve the behavior of the whole platform!
Well done!