I can explain it to you, it's not hard to use once you get the logic of it;
It means Linear Interpolation, basically moving a object from A to B in set time, in application it looks like this : lerp(A, B, x), x being the progress of the movement, it goes from 0 to 1, 0 means it didn't start, 1 means it's complete, 0.5 being the middle;
I believe that can solve your lag problem, because once the destination is reached, it wont need to update the movement every tick;
I'll take some time to craft a template once I'm home