i believe gif uploads to contribute to lag as one of the reason 1k gif hats ( I believe ) is because too many people began to get them and therefore they stopped them to prevent too many on the server, even if it does not contribute a lot it probably still does over all

To reduce lag and freezing on classic u can do a lot of things such as turn gif , weather , indicators or names and chat off which can greatly reduce lag.
However delay on the other hand is a lot different to fix as it matters on your location , our broadband speed and the server signal back speed. The further U are from the server the further the signal had to be sent and take longer , although You can speed your own speed up by paying more and more for ur internet the servers speed is constant meaning it will always be at that rate unless graal owner decides to upgrade servers.

If I'm not mistakes there was a post not long ago saying that server upgrades where possibly going I happen near the future however we never know when that might be