Over the last few years I’ve been doing that.(not local)
Using a map, (nirvanna sell a handy laminated one that covers
box hill to pitch hill++) you can plot a cracking circular ride starting @Mickleham to Ranmore Common,
North Downs way to Newlands corner ,Winterfold -Pitch hill – Holmbury Hill – Leith – back over Ranmore to Box hill.
I think on the map it’s classed as the nirvanna killer loop.
I always start North of Dorking = less driving.
Do it either way round.
It’s taken ages to get it to flow but if you look there’s loads of singletrack around the bridleways, some cheeky, some not so.
There really is loads of stuff away from the trails you mentioned,
Every time I go I find something new.
Take icj up on his offer.Have fun.
It’s a lovely place to ride.