Rides out of London always suffer from that problem (my own DIY 200 is awful on the return since it's just the A1010 then A10, lovely going North at 6am, awful coming South at 4pm).
Lovely routes out of London exist but they often don't make good Audax routes, e.g.
Unsuitable for sending hundreds of cyclists down at certain times (what's good for one may not be good for many)
Impossible to write routesheets for ("47th unmarked R turn") and you can't rely on everyone having a GPS
One person's ideal route is another person's hell (and vice versa)
For RRTY (from London) the best thing to do is leave early and return odd time or plan a route that ends at a convenient train station just outside M25 and take train back.
Rides out of London always suffer from that problem (my own DIY 200 is awful on the return since it's just the A1010 then A10, lovely going North at 6am, awful coming South at 4pm).
Lovely routes out of London exist but they often don't make good Audax routes, e.g.
Audax routes are very often a compromise.