Node amount restriction in IEEE 802.11s mesh network

Hi,

I read that IEEE 802.11s mesh network has a restriction for how many nodes it consists of. It is supposed that the number of nodes in IEEE 802.11s mesh network does not exceed 32 nodes or so.

Is it HWMP protocol restriction? Or what is it related to? If I turn HWMP off and use batman-adv instead, could it overcome such restriction?