[zer0defex]

Nice work, looks pretty solid. If you want to offload the responsibility of determining which GA metric events signify a potential spike, you could abstract it out and instead make the plugin use GA intelligence event alerts setup by your analytics team. This would help keep the respective subject-matter experts in their realms of expertise ideally allowing for a more on-going tailored approach to what, where, and how can trigger scaling fluctuations and the dev team isn't responsible for on-going management of the scaling trigger rules (well, to a certain extent).

Just a thought. I know you abstracted it out the way you did so as not to tie it to just GA, but if GA is your analytics platform of record, it could be worth pursuing. Cheers!