Turbocharge podcast feed not working as expected?

I have a podcast RSS feed with 278 episodes that takes a very long time to load. https://healthydebate.ca/feed/theroundstable

When I turn on the setting to “Turbocharge podcast feed” it doesn’t appear to remove the itunes:summary or the content:encoded from podcasts later than 10 episodes, as described on the support page: https://support.castos.com/hc/en-us/articles/360018923239-Turbocharging-your-feed-to-maximize-available-episodes.

The host (WP Engine) says that the feed URL is excluded from the cache.

Any troubleshooting help would be greatly appreciated.

The page I need help with: [log in to see the link]