This house built 1954 had no earth to lights, I had a problem as when the kitchen was rewired, they forgot the lights, and the electricians rightly refused to refit the fluorescent light as it was not class II, so I required a class II light, I found an internet site which specialised in class II and ordered a 28W 2D lamp, when it arrived it looked just like all the other 2D lamps found in the like of B&Q but with the double square sticker.
I can fully see your point, it seems a lot of extra money for what seems to be the same, however I note the ballast was fully plastic covered and it was likely the ballast type is what made it class II.
Switches were also a problem, the original switches had wooden back boxes, Bakelite covers, and there was no way any screw could become live, however the replacement switches used metal back boxes so required switches which had bungs in the socket for screws so you could not see or touch the fixing screws.
This really limited what could be used, and also the amount of rubber insulated cable resulted in too much leakage to use RCD protection, and when my mother with alzheimer's disease put a 4 outlet socket extension is a bucket of water as she thought it was on fire after seeing the red neon, so I decided to get house re-wired. I had the ability to DIY, but not the time.
The electricians doing the were able to do much of the work without ripping out plaster, he reused the existing conduit, however it cost a little more and resulted in some walls not having sockets.
With lights only it would be possible to use all wireless switches so only cabled under the floor boards not down the walls, however to do this you pay more for switches, so it is up to you to decide what to do, there are options, you could use a TV type remote control if you wished, although I prefer fixed switches. So you would need only two chases, one consumer unit to under floor boards and other to loft space.
It is up to you how it is done. However it does mean there is no need to flout regulations it just needs some thoughts on how to comply.