To reduce lag and increase efficiency of storage systems and farms (to mutual benefit of the server and players), make it so hoppers transport up to 25 items per tick.
This will reduce the amount of items flowing through hoppers as they will be able to keep up, making it so large storage systems do not get clogged or lag the server unnecessarily.
This may require a little coding, but I know it is possible as other servers have accomplished it in the past. I see no negative.
(This does not break item sorters, as the hoppers will just hold 25 items in it when powered and flow items exceeding 25)