When the remaining effort has no value, at the moment I can't edit it. I will be able to set it in this case.

When the remaining effort has no value, I can set a value.
I should not see a remaining effort badge on all cards, because for many cards I will never set this value (for example R&D or Tech cards).

Following options have been proposed:

• Add a button when hovering the card
• Show a (? => Flag> badge when hovering cards that don't have a remaining effort
• Have a way to set a remaining effort when editing the card (after clicking on the "edit pen" icon)