Should Tor 0.3.5 be the last 0.3.x since it's an LTS?
Tor 0.2.9 was the final Tor on the 0.2.x branch, and it was an LTS.
We could follow that pattern and move from 0.3.5 to 0.4.0.
The only downside I can see is that we hasten our arrival to Tor 1.0.0. But is that so bad?