Who is imposing ‘a maximum number of meshes’: GiD or the Iber calculation?
GiD without any licence allow 10.000 mesh nodes,
but the installer of GiD+Iber allow unlimited amount of nodes (the limit are you machine RAM and CPU)
Download and install again Iber 3.3.1, and do not modify any file of Iber (or the licence will be lost and GiD will limit again to 10.000 nodes)