The post you are reporting:
Re post 95: DfT 'comprehensive strategic plans for the White Cliffs site' doesn't sound terribly much like a customs facility due to end in 2025; neither, for that matter, does Mrs Elphicke's growth and development. (Oh, and I hadn't realised that July 2021 had already come and gone!)
Re post 97: the length of time lorries spend there depends on whether this is going to be a customs clearance site (longer dwelltimes but maybe with penal parking charges) or, as it sounds more like, an Office of Transit*/Border Inspection Post (shorter dwelltimes - apart from any unloading of POAO - and, I assume, free). Having said that, you do get into processing capacity** and the tricky subject of drivers' hours...
*Strictly, an Office of Transit is only for traffic inbound to the UK, which would tend to limit numbers.
** Especially if any clandestines pop out and occupy UKBF!
Re post 99: she is right though, the site has been part of WCBP for some time.