I'm not sure where people even get the idea that you can force the client to update your position, as the ability to do this would completely negate the design of the game itself (check every 0.3s). If there was actually the ability to do this, this problem can be solved immediately by forcing the client to update whenever any AE is finished casting. It's more like if you have the time to actually jump, or cast, or spin around in a circle or any other thing after you cleared an AE you obviously cleared the AE with a rather comfortable margin so even with the lag, you'd still comfortably beat the AE. Given the client doesn't even get to interrupt a spell you cast while moving even though it's literally impossible to cast a spell while moving in this game, it's pretty safe to assume your client has no ability whatsoever to force anything to happen on the server.