There's supposed to be 8tph (4 x WGC, 4 x HFN/SVG) on Saturdays, and 6tph (4 x WGC, 2 x SVG) on Sundays. That was 'implemented' in May last year. I think it ran okay first couple of weeks and then there were constant cancellations as drivers were moved to mainline services to try and even the misery of the new timetable. In July the service was cut to 4tph both days, but to do that GTR simply removed some trains and left the others at the same time. That left an odd timetable with gaps of 10, 20, 10, 20. In December these 4tph were retimed to be evenly spaced at every 15 minutes. I believe they're currently aiming for May 2020 for the reintroduction of these services.