Good to see it worked out, looks neater than running it up the side of the stairs.
That downstairs extension seems a bit of a dogs dinner, you don't need 2 cables connected to the external master. Cutting down on connections should give you a better set up. Maybe the builders put a 2nd cable in as a fall back in case one got damaged during the build. If one of the cables coming in from the external master is connected to the 2 & 5 then the rest of the extensions should fit to the F2 & F5. Meaning you should be able to do away with intermediate joins that are currently going on with those screw down connector blocks. You'd also connect the upstairs extension to the 2 & 5 connections as that is unfiltered for the extension feeding the modem connection.
Maybe that new downstairs faceplate isn't intended as a master socket replacement though. What I would have done is put a regular NTE5 master socket in the downstairs hall as that would have had an A & B connection to receive the connection from the cable coming into the property along with a vdsl faceplate that fits over the top which has an unfiltered connection for the modem extension and the bottom removable section of the NTE5 has connections for other voice extensions. Alternatively, you could use the new all in one BT Openreach MK4 VDSL/NTE5C Combined Unit.