I'd probably need to watch the entire thing to really get it! But fair enough, I get the gist of it.
Zooming out, going back to the root issue: the perf impact of writes on reads does seem weirdly oversized: my P50 on CheckPermissions is ~25% worse when there's some write traffic (6ms->8ms) and my P99 is almost double (76ms -> 140ms). Is that to be expected, or does it look shady? Maybe having some open-but-almost-unused gRPC connections for writes is impacting read latency somehow?