Limits for developer instances have been updated and are mostly provided by the API, except for message size.

The limits we display in the UI for a developer/"trial" instance should reflect the new limits. These limits are noted here: https://docs.google.com/spreadsheets/d/1W4H1IgDXKv24Sf7aWeqeAqxjKVj8EJB9giYN9obqPgU/edit#gid=1963544753