If you happen to spawn the Wither boss in a small spatial dimension, the boss may eventually break some matrix frames, enabling the player to wander in an invisible labyrinth.
I know the matrix frame is set to be unbreakable with a resistance of 6 million but well, that boss can't read Java :)
maybe we should just extend bedrock...
I couldn't get the Wither to destroy Ender IO's Reinforced Obsidian while it has a much lower resistance. Maybe that's due to something else, like opacity.
Bedrock is actually not even its own class, just a default block with .setBlockUnbreakable().setResistance(6000000.0F). So more or less identical to our block.
The wither explosion is actually calling Block.onBlockExploded, so maybe also override it?
But I did not find any custom handling for bedrock in the default implementation.
The thing is the Wither's explosion seems to be unable to "normally" break a matrix frame. It looks like it only happens when the Wither has not enough space around him. I spawned one in a 3x3x3 spatial dim so he was taking suffocation damage. At some point, after quite a few explosions, he managed to destroy the matrix. So maybe that's another mechanic than onBlockExploded, I don't know.
As I said, I couldn't get a Wither to destroy a 3x3x3 coffin of Ender IO's reinforced obsidian. But that only works if this coffin is surrounded by blocks otherwise the Wither will escape the coffin by going through it.
Prevent matrix frames from explosions.