At the moment, OpenBlocks uses the generic OpenModsFakePlayer-ish fake player to perform build checks. By relying on this Fake Player, other mods listening to this event won't be able to proccess the event as it would do for real players, since it doesn't store any reference to the player.

My suggestion is that the builder blocks store who placed them and use this info in the events. So, instead using your generic Fake Player, it would use a custom FakePlayer with the GameProfile (or only UUID) of the player who placed the block in the event. That way, ANY other mods listening to the break event will have the right info instead just a generic FakePlayer to handle.