You don't need to find a staffer waving a card; they find you. As you descend the stairs or escalator into the main immigration hall (past the waterfall & spindle whorl), there will be several people in bright blue YVR vests intercepting you with CANADA printed on the cards. If you missed them, maybe glance up from your phone. These staff meet all eligible flights.
You need not use the NEXUS lane, although it's definitely an option for those members. There's a separate bank of the regular PIK kiosks to the far right of the hall reserved for the Int to Dom (ITD) customers. They generally have no lineup and are as quick as using the dedicated NEXUS line. If you have NEXUS, you have the freedom to choose between the fastest line.
The process remains faster than exiting normal or taking the Level 4 corridor at the right exit of the baggage claim hall.
For those claiming the process is "a mess", think about the growth that AC and YVR have experienced the past few years. Spend some time at the airport learning about the construction underway to complete the ITD process within the terminal without the need for buses. Offer any helpful suggestions on how you'd have foreseen the situation, and/or how you'd improve upon it. ITD passengers save an average of 24 minutes in connection time (latest figures to January 2019), but perhaps those averse to messes might wish to spend that time in a nice zen-like walk along the old route through customs and a subsequent bag drop and rescreening.
Totally your choice, either way.