Yes, I have seen a couple sets myself on what appear to be HKRV trains, as they are usually pullings lots of Canadian grain and lumber (lots of SRY cars). I saw one DPU assisted train last Friday afternoon taking the Chico siding for a northbound Z train and another one about a week or more prior. Each one I have seen has had a GE and an EMD for DPU's. Actually I believe this practice has been allowed for several months now, as I have heard others mention that they have occasionally seen DPU's on southbound Valley Line trains.

SP/UP could still use helpers north of Dunsmuir for braking, since I used to see that from time to time, but as far as I know, UP still cannot use helpers for power on northbounds out of Dunsmuir.