I don't think we need another flashlight sub. The time to make a new sub is when the old one gets cluttered up with a particular subtopic enough that there are basically two separate groups of participants annoying each other. Then the subtopic can split off. On lemmy, there are too many subs rather than not enough, and federation makes it even worse. I'd say for now, it is fine to post whatever you want about Hank lights on c/flashlight. We all like Hank lights so no one will mind unless the volume gets out of hand.
Lemmy really needs some sort of multi-community aggregator; this is happening around many different topics and it would be great to group them into a single feed.
I think it should be user based; allow users to group multiple subscriptions under a named group; then you can choose that group to see a feed filtered to all those communities.