Questions on underground Wireless Flow meter install

I will be receiving my wireless flow meter in a couple days and want to install underground in a valve box. I have been going over install instructions and read this:
"Based on the determined direction and layout of pipe, begin to dig where you guess there will be 17 inches of straight pipe between your valve box and backflow preventer"

Does Rachio want a straight shot of pipe going into controller valve box AFTER the install of the flow meter (I’m thinking not) or just saying that it needs a straight section of 17" for the flow meter install? Asking because I have two 90º elbows that will be between the flow meter and manifold control valve box after the Rachio Flow meter. I will have 10 feet of straight pipe before any elbows going into manifold valve box.

Rachio Support, would sharkbite couplings be acceptable on the flow meter I instead of the orbit push connectors mentioned in install directions?

Thanks
Ron

@Bytored - I believe the 17" is the installation area for the flow meter and fittings. It shouldn’t matter what is after the flow meter.