Build an abstraction layer over different consensus flavours
In #25979 (closed), there was a bug in sbws because the ns consensus flavour has exit policy summaries in the consensus, but the microdescriptor consensus has exit policy summaries in microdescriptors.
The code to abstract over these differences is reasonably simple, but it's hard for people to read the specs, find out all the details, and implement it correctly.
For an example, see: https://trac.torproject.org/projects/tor/ticket/25979#comment:4
It would be great if Stem included an abstraction layer over the consensus and descriptors, and just returned the attribute regardless of where it came from. (Maybe we could include this code in Tor instead, but it would be a major effort.)