Option to start as a bridge by default, but change to relay if bw is super-high.
There are some minor ongoing problems with Tor speed, which has cascade effects in user adoption and accessibility.
If there were a type of node that starts as a middle relay and changes into a bridge if average speed in the past day were unacceptably low, that could dramatically improve mean transfer time. And then, if conditions improved, a convertible node would change from a bridge back to a relay.
Given that bridges become unusable in the most high-risk areas in just a few days (Winter & Lindskag 2012), its side effect of increasing the bridge population would be a very positive thing.