The fibre is blown on demand, there's not an abundance already delivered to cabinets, and some cabinets have WDM kit in them to reduce fibre count from aggregation nodes so in at least some areas there isn't an abundance available from the aggregation node either.
Sckipio are a chipset manufacturer. They supply reference designs for CPE and chipsets for some of the G.fast nodes Openreach have tested. The actual nodes, at least one of which includes Sckipio's chipset, are produced by the three I mentioned below.