On collada import a -1 layer_index from CustomData_get_layer_index (CD_MTFACE) was used. This then managed to overwrite last mface's data with uv-set's name so at least it gave a clue where to look for :]
On collada import a -1 layer_index from CustomData_get_layer_index (CD_MTFACE) was used. This then managed to overwrite last mface's data with uv-set's name so at least it gave a clue where to look for :]