Current configuration of custom preciousstone:

title: Dungeon Field
block: 7
radius: 30
custom-height: 30
grief-revert: true
grief-revert-drop: true
no-owner: true
welcome-message: true
farewell-message: true
prevent-place: false
visualize-on-rightclick: true
required-permission: true
mixing-group: 1
cuboid: true

Expected result: Player placed blocks would be allowed, but counted as grief. Upon grief-revert reset, such placed blocks would disappear.

Current result: grief-revert:true does not allow users to place blocks when prevent-place:false is present in the config.

Adding "grief-revert-allow-place" flag on next release

Gratzi!