I bought the Sturgi-Safe adaptor on Amazon.
Sturgi-Safe RoadTrip LXE Low Pressure Quick Disconnect Conversion Fitting
https://www.amazon.com/dp/B07BN7DVN8..._yHbEBbPM4QJCE
It works perfectly, and to original adaptor is untouched so I can easily switch back to the small bottles if necessary.
The part itself is $35, but leaves you with no assembly work to do or any unknowns. It just works. They do get you for another $10.49 in shipping.
FWIW, I bought the one with the hose, but wish I bought the hose separately. I could have save a few bucks.