Has anyone used this module? NEO-M8P-2 , it is avail for about 86 dollars not and it is RTK next generation that can kalman filter gps readings into a finer group and also connect to other NEO-M8P-2 to establish a point of reference for centimeter accurate positioning.  I would like to get these into a outdoor robot so that I can setup a geo fence and maybe have a better lawn mower bot as well.  I would gladly buy and send one to EZ-Robot / Synthiam to integrate into ARC .

heres a board from sparkfun with this module , obviously some mark up here. https://www.sparkfun.com/products/15005?_ga=2.112589700.1614778552.1552239910-1220536756.1551811452

promotional video from ublox https://www.youtube.com/watch?v=rdVT8FxyAlY

Here is Ublox page docs https://www.u-blox.com/en/product/neo-m8p-series