I think it would be nice to have a reward for people who complete the checklist. At the point where you’ve been through all those steps you’ve committed quite a bit of effort of time and effort into Monzo-ing your finances.
I thought the following might serve as good rewards:
Nice idea.
I can’t see any of the those three being offered though due to costs.
Maybe just get some Monzo points when they return (if).
The cost issue definitely makes sense. I also think it would be extremely wasteful for everyone to get a card when they join and then get another one soon after for completing their checklist.
I just think there has to be a better option than badges (which also seem to be invisible and of absolutely no use)
Take a look at the first post in this thread:
Could the reward be factored into this?
Bad idea because not everyone can be full Monzo through no fault of their own.
I can never be full Monzo as I’m self employed and don’t receive a salary from BACS.
For me to atget that “reward” I would need to close down my business and get a full time job, sod that 
How is a ‘special’ card of ‘use’? Offers no additional value that I can see?