Involved in the transfer of galactofuranose (Galf) onto an alpha-D-gluco-configured acceptor substrate to form a beta-1,6-linkage. It uses n-octyl alpha-D-glucopyranoside as an acceptor substrate for the addition of galactofuranose from the donor substrate UDP-galactofuranose. It is not able to use beta-D-glucopyranoside isomers. Bacterial outer membrane biogenesis; lipopolysaccharide biosynthesis.