I put the faceplate on yesterday and it hasn't helped - you're right - but at least it's all a bit tidier.
New modem/router setup just now. Took me a while to work out how to accept pings (TP-Link hid that option away nicely), but it's now sorted so my quality monitor should carry on working.
No change to the speedtest results in general (I am focusing on the green results which I understand should be nearer the yellow):
Nevertheless, fingers crossed this fixes my packet loss issues. I shall give the connection some hammer over the Easter weekend to test.