For Yau 6 I do F2C, Cross plus an F2L Edge, put them on right bottom and right back, do centers, than I do 4 edges including one adjacent F2L edge to the already solved one, solve those two F2L slots in back, use the 2 open slots to solve the L3E, and solve like a 3x3
I have no 7x7 currently, but I would do F2C, Cross plus 2 adjacent F2L Edges, put them on right bottom, right front, and and right back, do centers, than I would do any 4 edges, solve two adjacent F2L edges with their slots in back, use the 2 open slots to solve the L2E, and solve like a 3x3
goodish for 6x6 badish for 7c7