Since the last update, there has been progress on a few fronts:
- The async support for Flask and Django in Rockcraft is waiting on documentation review and is otherwise good to go. The PRs for 
paas-charmand Charmcraft are waiting for this PR to be merged so that the rollout of this feature is smooth. - We have created an initial version of a spec to support Express.js. Please take a look and provide us with any feedback.