To add to what Pat said, If your game is a homebrew, you might not be able to add the sheet to the shared library. It depends on if there's a public site for people to access the rules. If you upgrade to Pro to design the sheet, prepare for it to take longer to build the sheet than you expect (unless you are taking someone else's sheet and just making a few tweaks - if this is possible, i strongly recommend it), Once you do have the sheet ready, as Pat says you can downgrade from Pro and will still have access to that sheet. But you wont be able to keep the sheet if you copy the campaign or start new campaigns. So it's a good idea before downgrading from Pro to make a bunch of copies of the campaign, with the sheet active, give you flexibility. In conclusion: yes, it's very practical to upgrade to Pro temporarily to make you sheet, and then keep using it after you downgrade.