Looks like the Mob Masher still is broken by the wither, so I'll make them along with the Fans, Absorption Hopper, Tanks etc all unbreakable by it.

This appears to be back in 0.3.13
(using Forge 14.23.5.2838)

done

Hey vadis365, I think you forgot to add the Wither protection (override for canEntityDestroy()) to the masher itself (BlockSaw).

Hello,
Haha - good catch, thanks. I must have missed it when I was changing it all up ;)
Fixed in 0.3.9 (now available on curse).
Cheers,
Me.