Selecting All Instances and then Top Day will give you the highest upvotes for all federated instances for 24 hours. I used this to find and subscribe to communities i like.
BUT - Be aware that there is known bug in the current version of lemmy that causes an automatic refresh of new items.
This is my preferred method of scrolling as well. I did spend a large amount of timing blocking communities that I didn't want to engage in, but after a few days of blocking it has been pretty good.