This sounds great! I'm no expert but it seems that the postgres documentation disagrees about the process for enabling the extension -- "The module must be loaded by adding pg_stat_statements to shared_preload_libraries in postgresql.conf, because it requires additional shared memory. This means that a server restart is needed to add or remove the module."[1]
What I was really looking for was a ballpark estimate or guideline of what additional resources a server would need to run this extension.