Yes, agreed. I had studied the documentation carefully and had watched the videos too and noticed the insert was there in all cases.
I wouldn’t worry about that. SharkBite’s documentation clearly says removal is optional. Since all testing by Rachio with SharkBite connectors had the insert in place, I can’t see any unforeseen long term problems either. Liner insert removal was just something that I thought I’d highlight as an option. One of my zones was already close to not having enough water pressure so I wanted to minimize the pressure loss from addition of flow meter.