Next #Holos release will use Bloom filters (https://en.wikipedia.org/wiki/Bloom_filter) for sync. The relay filters activities, only sending those from accounts you follow and from the local timeline.
The filter is sent each sync and never stored. The relay still has no knowledge of your followings.
Test: 26 followings, 32k pending activities filtered down to a hundred (99.7% reduction).
The public timeline goes away as a result. #HolosDiscover will replace it with content tailored to your interests.

#HolosSocial