Yes! I just thought of this as well, I think it'd be great! Full support!

I remember the conversation of having like an All Characters% which would just be unlocking all the characters, but then I think you suggested that it would be grinding SEGA Miles which would be monotonous. Maybe an Opa-Opa/Alex Kidd% since they cost the most? But the judgement is up to you and the other moderators.