This is a wonderful suggestion, but from my perspective it would be hard to actually judge for the following reasons:
-This would take a lot of staff and time to judge, Staff do not have all the time in the world to give out a monthly prize they have lives outside of Manacube.
-Would people be online while it's being judged? due to party claim they would have to give a tour and unlock doors and such.
-Is it going to be easy to supply co-ords to trusted members, If you put them on certain sites (ie discord) you could attract unwanted grievers. Which could be an issue.
-Also would the bases have to be double checked if they have been submitted the competition in the month beforehand, this could be quite hard to manage.
Yet again this is a great idea but sadly it's a tad unrealistic.
Thankyou for reading my view on your idea, Have a great day or night <3