Do keep in mind both lemmy and kbin are in the alpha stages and both were relatively slow/calm before the whole reddit thing happened so the devs were caught by surprise.
Try out one of the kbin instances and see what you think. It has lemmy + kbin + mastodon integration. Some of the kbin instances are listed on here: https://kbin.pub/en
I just opened user registration on my kbin instance yesterday so it hasn't been added to the list yet, but feel free to try any of them!