I am wanting to know if the MovingBase/MovingRover setup is any less accurate than a FixedBase/Rover setup. Other than having an additional receiver in the filed is there any downside to using a moving base?
It is less accurate a moving base compared to a static base, but might be still good enough for your application.
If you really have a base that is moving:
The moving base position can move between the time that the correction was generated and the time this correction arrives to the rover.
Also the GNSS measurements of a moving device tend to be worse than the ones of a static one.
Even if you use moving base with 2 static base and rover:
The fact that they are expecting to have a moving base adds some extra error to the calculation.