Moving this bug to POST for triage into Satellite since the upstream issue https://projects.theforeman.org/issues/30286 has been resolved.
Verified with Sat 6.7.2 snap 2.0. This is hard to verify as there is no real reproducer nor is it concretely specified how this bug actually manifests. I had a Satellite, an external Capsule and a Host registered through that Capsule. I tried to cause huge sync load on both Satellite and Capsule. During this time, I tried to also run different tasks on the hosts, e.g. ran a command through remote execution. I measured systems load which was high due to ~25 repos being synced at a time but nothing was unusually or unexpectably slow. Most CPU time was taken by pulp workers which is expected when syncing. I haven't noticed any files growing too much (cache grew a few GBs and shrinked after the operation) or lowered responsibility at any time. The remote commands have been ran correctly and almost immediately. Dynflow log looks ok. To conclude, I haven't noticed any issues while doing a large Capsule sync.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2020:3255