I have an N.incei communal and was surprised by one of the H.incei's who made his/her silk home inside the top of the bonsai hide. Well I might have something to do with it. Cutting a opening in the top branches The rest dig like mad. All are still alive.

I think these spiders give a different result every time, I have had good results and I have had not so good results!

I think it comes down to how your spiders are feeling that day?!

They are communal, I have two communals, both have had egg cases and given me slings, all the other females except the the slings as there own, even build webbing for them.

They are "pet hole" or "Pet webbing", the more substrate you give them the more they dig and the less they web on top of the substrate, the less substrate and the more hiding places you give them the more they web on top of the substrate.
But they are still a species that is not seen that often, the food just disappears, and there is the odd occasion you lose a couple H. incei