Ok? I'm surprised your work lets you build a whole product ontop of google sheets, then. Also, why did you delete your original comment on not having a server?
I deleted it cause I realized this thing has a server (probably). Was mixing it up with other people's projects that didn't have one.
They're internal tools, but big ones. And I'm surprised too. You won't hit too much resistance doing things the well-supported ways, but for some reason there's no well-supported way to run a cache.