PlayStrategy Puzzles

Is there any plan to add new puzzles soon or to introduce more difficulty levels for the existing ones, like Lines of Action?

Thanks!

Also, I'm curious about how the Elo rating changes. Sometimes you gain points, and sometimes you don't. So far, it seems that more complicated exercises give you more points, which I think is how it should work, since some exercises have more variations and possible moves than others.

For example, I just solved this exercise: playstrategy.org/training/linesOfAction/KBWTe

The solution wasn't straightforward, but my Elo rating didn't change at all.