repro procedure: Join two clients. Watch bandwidth (debug menu 4) usage on master. On live it's around 3 k/s, on danly-perf it's over 10 k/s (sometimes ending up with a persistent death run which degrades IK fidelity)
Debug 8 will show BW 0.00b/s for tiles not moving on live, but around 40-80 on danly-perf
Images are perf branch and (a slightly old) live branch screenshot of debug 4 and 8 showing the bandwidth usage difference.