One user for syncing multiple real users using channels

We have mobile application which use 10000+ users. Application use Couchbase lite to store users data.
Currently we would like to upload users data using Sync Gateway.
We have an idea to create one user to sync data using replicator, but in sync function we set up a channel for “real user” dynamically depends on channel name stored in documents.
So one user to sync data, 10000+ channels set up to this user, but on sync function user has access to only one channel.
Is our approach correct?
I see in documentation there is Guidance Limit 1000 Channels per user - but this is limit for sync function or for data stored in server Database?

What’s the motivation of using a single SG user for the 10000 ‘real users’, as opposed to setting up a SG user per real user?

You could definitely assign each incoming document to the a channel associated with the ‘real user’, but unless you’re actually authenticating the users separately you don’t have any security there - any user could read and write data as if they were any other user.