I guess you can hit it at it two ways. One would be to just except there will be lag and go on (lol). The other is find out how bad the lag was. To do this, the client will have to send a time stamp when the client has requested to move. The problem with that idea is that a user could hack by changing his or her time clock a few time resulting in the system speeding up or slowing down the time stamp msg. This happens to a lot of online game that try this. The other way around this is to just figure out the users ping/speed at whitch the client sends data and then take that off the lag between calls.
So, taking your example. The user moved for 1 sec at the speed of one, but the lag caused the server to think the client ran for 1.1. To get around this, server ping client a few times for a base data speed, then except new data -ing the data rate lag, so server now thinks the client ran for 1 -+.1 sec.
That build does (good luck trying to find it lol), but I did some collision rebuilding, so not sure if’ll work with the new patch I’m about to put up. (maybe)