Compression during replication(sync)

My understanding is that we can set compressResponses to true(default) to enable GZip compression of HTTP responses for the sync contents. My questions are these:

  1. Is this available for both iOS and Android implementations with Sync GW 1.1?
  2. Does this compress both the push and pull replication contents?

Thx

YES

YES

DELTA SYNC
In CBL 2.5 and SG 2.5 there is now Delta Sync on the EE version. Delta Compression/Sync send only the changes in the document not the whole document like before.
Docs on Delta Sync: https://docs.couchbase.com/sync-gateway/2.5/config-properties.html#databases-foo_db-delta_sync