A minor detail : On all approaches similar to the one shown, one gets glideslope callouts e.g. already on the "parallel" AFI-NIVOR leg (approx. at the point marked with an X in the chart excerpt). Even if the HS 1 source selector is still in the RNAV position. This is of course not applicable and doesn't make sense.
One idea would be to suppress Glideslope callouts if the HS 1 source selector is still in the RNAV position and send them only if it is in the NAV position.