I would think the low pass filter is also in the G.Fast pod as you don't want the signal travelling back towards the exchange. How they connect up will work in the same way as FTTC except G.Fast is just that much closer to the PCP. Having the pod on the PCP will also reduce distance for many people, at my old address the PCP was a good 20 metres away from the FTTC cabinet, so adding 20 metres of distance, at my new address it's around 10 metres. With G.Fast being more distance dependent than anything they've hacked across decades old telephone cable before, saving just a few metres of distance will make a considerable difference. Presumably why they've gone for attaching the POD on the PCP rather than extending the FTTC cabinet, which would be easier as the power and fibre is already there.