Caching data on server

In our app we run quite a few subscriptions on the initial page.
This drastically reduces the load time, which is also caused by our deployment, when database is in a different region as the app (do not ask …).

Many of these subscriptions actually serve almost static data that needs to be only filtered for the current user.
The idea we had, was to cache the data in the memory and then serve it to the user.

The problem we have is that subscriptions can return only Cursors and we cannot filter Mongo Cursors.

Any idea here please?

PS: We DO use subs-manager on client and have other optimisations, what we are solving now is the initial loading time.