Regarding W46 safety recall, there is a complete service procedure on NHTSA website (FCA Revision (2) July 2020), the URL link is https://static.nhtsa.gov/odi/rcl/2020/RCRIT-20V334-3759.pdf
The full service procedure is quite involved because it involves powering down the 12V circuit, do a high voltage safety disconnect and removing (2) belly pans to access the "isolator post" from under the vehicle. If there is no obvious corrosions (see Fig 20 of the service procedure), adding a "special" foam washer (from the passenger compartment, to prevent future water damage) will fix it. The washer/gasket seems to be a double-sided adhesive washer (see Fig 51 of bulletin, FCA part number CSALW462AA Gasket Kit). I don't understand how such a simple part can become such a big hassle to distribute to the dealers. Obviously this is a safety recall, you must let the dealer to perform the inspection and the necessary repairs. But if you are frustrated about the run-around and delays, and just want to take a peek-a-boo, you can start from Fig. 21 (disclaimer: do so at your own perils) remove the seat rail plastic cover (first, pry off a small plastic plug that holds it in place), pop the rear door plastic sill with a door panel removal tool (Fig. 22), gently pull the carpet (Fig. 23) to expose the 12V cable terminal (Fig 24). If there are no signs of liquid incursion or corrosion, you are in good shape. W46 is presumably caused by liquid accumulating around the terminal and seep under the 12V cable terminal, down to the underbody causing nasty corrosion and eventually fire. Dry is good. I attached photos of the area around the 12V cable terminal (Isolator Post) in my Pacifica PHEV, it looks completely dry and shows no signs of liquid incursion. Dry is good: don't put wet umbrella, ski boots, juice or milk around that area. The W46 Foam Gasket fix is to add a gasket under the 12V cable terminal so that (future) liquid cannot seep past through it to the underbody to cause corrosion and fire. It is better to not let liquid to get there in the first place. Be creative in keeping this area dry such as using plastic bucket for umbrella or using rubber floor mat that can trap some water.