No, and it wouldn't help much if there was. The biggest benefits come from running the metadata cache locally, or at least on the same local network. The cost/time savings come from preventing external API calls.
That's true if it was local. A 2 million key response from an externally hosted MimicDB instance would probably have to be split in 2000 requests and take the same amount of time.
Send me an email nathan@nathancahill.com and I can show you how to set up a local cache. It's quite simple.