Without having an ethernet cable trailing across the room are there, to your knowledge, other options?
If not, perhaps BT should advise potential customers thinking of getting 900/500/300 that it'll work.... not just that it can be delivered to a hole in the metre thick granite wall my cottage is made of.
Still, there's a lot more serious stuff out there at the moment.
You’re very welcome Kilgeever53. I ended up purchasing a WiFi mesh system (Orbi brand) with a backhaul between satellites to ensure maximum strength and speed of WiFi connection. This has worked for me and on WiFi I’m now getting 400-500mb throughout the house (I have full fibre 900). The satellites in a good mesh system will also give you ports for you to connect them directly via a cat cable with any devices (if you wish to do so) which will provide a solid connection. The only way to get even faster speeds than this will be a cat cable from the router to your device but in most houses this means drilling through walls which is not so practical 😞 I hope this info helps a little and feel free to ask any other questions you may have.