Dredges locker teleporting ability heavily depends on RNG, so there isn't much to master there (aside from the whole grabbing people as they run past thing) so you should focus on learning how to zone people with your remnant, e.g. place your remnant on one side of the loop and then push them towards the remnant from the other side. Keep in mind you are much slower after you have placed your remnant. That's pretty much all I can tell you.