Thanks! I'm glad you enjoy it!
An A4 version (and a proper screen version) are on my todo list. I of course have no way to test the A4 version, but I will try my best. In the mean time, I believe after you print it, you can trim the edges smaller and it should fold a little better.
As for charging, I would rather keep it free. Any money / donations should go towards Tana Pigeon so she can keep making awesome Mythic content.