Many use the Pasco Rambit tools to bore out glued plastic fittings, but it is poorly designed and does not perform well...it grabs, it bends and prangs, etc. While it has a low pricepoint, you're a professional, so get a pro tool! Reed's Clean Ream is our favorite. They make versions to bore out closet flanges with crappy plastic or steel rings that corroded out and you can push glue in a street style abs/stainless steel replacement flange.
And yes, they make small ones for PVC water lines too.
And yes, they make small ones for PVC water lines too.