yes amp fx send to Rack gizmo input, rack gizmo output to loop 5 in, out 5 to Amp fx return
and for the effects before the amp
guitar to rack gizmo in 6, rack gizmo out 6 to rack gizmo in 7, rack gizmo out 7> to amp guitar in
that will give you 5 effects in the amp fx loop and 2 before the amp
you can obviusly add the buffer wherever suits your setup the best