While I usually get he Z4 pretty early, it's always possible to lose radios prior to that clearance, and have to fly last known assigned alt/clearance to IAP.
Sure, no objections here on my side, theficklefinger.
As a practical matter, coming from any distance you would usually get that or the other STAR. They indeed add flight path miles (at least arriving from the NW to avoid LAX inbounds. But, V197 can avoid LAX inbounds, albeit with more handling by the Ontario area SoCal folks. And, if KONT is busy then V197 conflicts with the Pomona SID. But, KONT is often not busy, especially these days.
If filed and approved by all means I don't see any reason not to fly it as it shortens the mileage quite a bit. In practical terms whatever the dispatcher has filed as ATS flight plan I'll simply follow it, I don't have time and resources to explore all possible filing options during preflight briefing however knowing the local particularities may prompt a request to ATC while airborne to reroute if feasible.