There are actually couple of reasons. One being the symlink handling code in the xsync crawl was incorrectly generating the journal entry in the changelog. The other reason being a perceived slowness. When the hybrid crawl is the main crawl, an FS crawl is done every 60 seconds.
Symlinks were not getting synced to the slave.
1. The symlink handling code was fixed.
2. During the main crawl a sync happens every 60 seconds -- this was observed while reproducing the bug.
symlinks are synced to the slave.