They should allow beacons/building on select exoplanets. Once the exoplanet is gone, all materials left behind are destroyed. The build or builds with the highest prestige are added to a scoreboard and the top one(s) showcased. These competitions could be restricted or unrestricted. Example restrictions could be radius cap around beacon, total plot cap, above/below sea level only, no machines, player’s choice etc. On exoplanets the Chrysominter gains prestige for the build instead of providing coins and logs all items deposited.
All of the builds could be stored on a blank new planet void of resources as a showcase. In this blank world no blocks can be broken nor do HP, energy, or item durability deplete. A book similar to guild log displays involved builders, clan association, all blocks in the build, quantity of items ran through the Chrysominter, etc.
The planet would only be only accessible via the sanctum. Alternatively a special portal token could be given to the player with the highest prestige from the build. It would require no Oort to power. The player could choose to place this wherever they please, however a player made hub with all competition winners sounds nice. Leaving through any portal on this planet returns you to where you came from to avoid the creation of a free portal network.