The static mesh issue described in T65816 has been resolved by @Sergey in T60094. This commit fixes the last bit of the puzzle, which was two-fold: - A missing depsgraph update when setting `orig_object.data = new_mesh` from Python. Thanks @Sergey for providing the fix :) - Properly locking the interface while exporting. This prevents crashes as described in T60094. The previous approach of calling `BKE_spacedata_draw_locks()` was not enough.