Runway holding points serving instrument runways are positioned where they are to ensure aircraft or vehicles at the holding point 1) do not infringe obstacle surfaces for landing aircraft 2) do not infringe ILS sensitive areas during low vis procedures.
In the case of conditional line up clearances behind a previous departure then as long as visibility is good and there is no landing traffic then I see no reason for the conditional line up aircraft not to cross the holding point. It's up to the pilot to judge what is a safe distance between the other aircraft ahead. At night when runway guard bars are in use then it helps if controllers can ensure the red bar is suppressed when giving conditional line ups behind a previous departure so as to minimise runway occupancy time.
Reducing aircraft occupancy time on runways means less delay and more capacity and as long as it is done safely then everyone benefits