Will, a pressure test is a great idea. Any idea how you will increase interior pressure for this? I’ve seen some videos using everything from box fans to leaf blowers.
I have had good results using this sealant Geocel 28100V Pro Flex Crystal Clear RV Flexible Sealant - 10 oz, Quantity 1 (GC28100)You probably are already aware silicone while widely used nothing adheres to dried silicone. This makes it problematic anytime “recaulking” over old silicone. The Geocel sealant is non silicone.