Site Performance Issues and MySQL Strain

First of all, our company is a big fan of your plugin and this has been a great solution for our needs.

We’ve been experiencing site performance issues for some time and have tracked it down to this plugin. Primarily about every hour we get a huge spike that can be seen in New Relic where this plugin will jump from low milliseconds to over 19 seconds. We’ve also seen a direct correlation in MySQL overview for a task called MySQL rele_postmeta select that will go from milliseconds to over 90 seconds. These are massive spikes and will often times cause our backend to crash for a few seconds and slows down other areas. But this plugin is putting a huge strain on database operations and our site.

Here are links to two screenshots:
https://storage.googleapis.com/relevant-magazine/support/wp-stateless/stateless-1.png

https://storage.googleapis.com/relevant-magazine/support/wp-stateless/stateless-2.png

I would like to know if there is a way to fix or alleviate this problem, either through something I can change in the code or if this will be addressed with a future update? In regards to a future update, is there a timeline for when one will come or when compatibility will be updated? We are on version 4.8 and this plugin supports 4.5.9, and hasn’t seen an update in over a year. I can provide more screenshots and details if needed.

Thanks for your time.