To be fair he could always go his pocket dimension to avoid the blast and later escape, also according to his main article and some tales he’s very smart and sadistic Treats is a good example
“Weeks later, an observation tech made a note in the day's log. SCP-106 was observed to suddenly produce a large handful of small white objects, later identified as teeth and finger bones, and set the pile on the floor. It then sorted these objects in to what seemed random piles, later identified as separated by age of victim. It then stared at these items for several hours, then re-collected them.
The significance of this was considered unworthy of contemplation.”
So I think it comes down to this he could care less if the site blows up he can protect himself and possibly escape and he probably knows the Femur breaker is a trick but there’s still reasons and theories on why he still falls for it. He knows the Foundation will recapture him soon enough and here’s a free victim who is suffering a lot might as well get it. And a few theories from Reddit can be found Here