Just an idea but could not not stick mosaic mesh sheets to the former and trowel over with adhesive? Will make the base pretty solid and will follow the fall/fleet.. Then fit the mosaics as normal fixed to mosaic mesh. Not sure if 2 layers would be enough? Should get over any point loading issues and will achieve a 100% bed.
Think I understand what you mean.
Do you mean the rigid plastic mesh sheets that are about 30 by 30?
Do you mean stick these to the tile former and then level them with adhesive? Can you elaborate?
Thanks,
Daz