I can confirm what Superku said. On my Asus UX360UAK-BB285T I got the following results with bmap_createblack and bmap_blit:

sys_memory 65.6
d3d_texbmaps 1560.0
nexus 0.4/40
d3d_texfree 2557.0

num_bmaps 194

Error 2005 until MAX_BMAPS. After that d3d_texfree is 2549.0 and the engine continues to run.

With bmap_create I got:

sys_memory 841.6
d3d_texbmaps 776.0
nexus 0.4/40
d3d_texfree 3325.0

num_bmaps 98

Error 1005 and the engine crashes.