Interesting sections of route at:
19 to 20 miles - thick leaf mulch and moss on top of abandoned road for a long stretch plus Aldecar Road section was in a pretty grim condition last time I tried it ( tarmac with potholes and mountain of crap up the middle ).
30.3 to 30.5 miles - Pennsylvania Avenue, Tiptree always shite but usually passable.
34 to 34.8 miles - farm track. I haven't ridden this bit in years, new gates and fencing at Braxted end.
There may be more that I haven't spotted.
Tarmac based alternatives are easy to use instead.
I will be out tonight.