The tubing is 8mm X 4.8mm. One can buy PharMed BPT tubing on eBay from Kamoer.
I took the leaking 1st gen hose assembly apart and I don't see any reason why one could not replace the tubing. There is a considerable difference in pump output on the Kamoer between the silicon and PharMed tubing.
Since you upgraded the tubing. Have you had any problems? Like going out of calibration or stop pulling/push. It’s a good idea. How long the new tube has been running and running what equipment.