Nice Work! Are you hosting the WMS yourself? I'm hosting one for my region of germany in 0,25m resolution and it's about 100gb already. Whole of UK must be a pretty massive TIF.

I am working on a site for downloading and using high-res lidar data internationally. Maybe check it out if you're interested: https://hillsha.de/

Detailed down to the level of individual trees and houses. You can even see ridges near my house that might be from ridge and furrow agriculture:

https://en.wikipedia.org/wiki/Ridge_and_furrow