Server: Black list block breaking

I would like a way to configure what blocks a turtle can not break. Right now a turtle can break through everything short of bedrock even the spawn point.

I would like to be able to add block IDs to a config so that a turtle can not break them.

How would that stop turtles from destroying the spawn point?

You could make spawn out of, say, sponges (are those still in the game?) and ban sponges from block breaking? Although a sponge spawn would be nasty.
What is the point of this again?

Or add a world guard flag

Turtles are counted as players internally to my knowledge. So, if a player cannot break em, a turtle can't either.

I am not running a bucket server so worldgaurd is not an option ( if it is tell me an i will love you for atleast 15 mins :(/>/> )

Currently I’m using an FTB server
so my currently my only option is FIHGU for protection and this does not stop a turtle.

And have tested this a turtle will dig right through spawn and other forms of protection.

If possible i would black list more items that don’t naturally spawn. This would also prevent a turtle from accidently ripping through some ones basement.