Hello fellow Native,
Yes you have found that Audax in Suffolk is a bit spartan - thank goodness for DIYs.
There are some routes out of Bildeston, Suffolk Lanes Extravager is a nice 200k, Cambridge Audax Permanents have some nice routes through our patch, which I have been able to modify into DIYs.
John Thompson has some nice routes through Suffolk and Norfolk, based in East Suffolk I think.
If your brave enough to go over the boarder, the ACME Gang have plenty of routes. Sudbury Cycling Club have also pleasant routes from Long Melford.
I find making a DIY is most ideal if you know the area, I tend to include some favourite rest stops and eatery's.
Good Luck and have fun.
Regards.