I know Item Sets are no longer supported in the alpha client. However, editing an item set in the old client (supported) does not get reflected in the new alpha client (feels like it should since it should just be reading your item sets).
DarkRitual2 votesIt used to before when the Alpha client was still limited. Something changed that they are not updating/saving to the settings on the server like they should. This is incredibly annoying, and I hope for it to be fixed.
Chamuel851 votesI know there is a json file in the Config folder with yoru item sets, but changing that doesn't update the client. :(
DarkRitual2 votesThat was back when Item set files were stored and loaded locally. Riot had changed it to be stored server-side with your other profile and settings information, to make it easier if you play from multiple computers.
Chamuel851 votesThis is true, but even after that point, my json file was up to date. Was hoping it did some syncing between the files and server. I think there might be 3rd party itemset programs that they wanted to support.