I have noticed this problem for a very long time, at least since we got a GC GO server, or soon after. I have always had these little rubber bandings, and my guns doing the stutter switch, that never occurred in css or any other CS GO server.
When i went to some other servers, the SV was rock solid at whatever the server tick rate was, and never budged even in large gun battles. The highest choke was 2 %, but even that was very rare. GC server was giving me a max of 12 choke at times, and the SV was never at the tick rate of 128, unless at the spawn when round starts and no shooting was going on. The second shooting occurred, the SV started to plummet, which is when the choke starts, the rubber banding, etc. I tested a bunch of valve servers and other servers, and none of them do any of these things. Rock solid. I have not tried GC since you made changes at the time of this post.