@thwclw

The tire on this is TPU purchased from tonerplastics and printed on a chiron with a Volcano with a .8 at .88 outside perimeters and 1.4mm insideperimeters at a max speed of 50mm/sec governed at 15mm3/sec max volumetric E. So you can print TPU faster too.
As for switching from PETG to TPU or TPU to PETG mid print - I have not tried that. Some materials stick to each other - some don't It might delaminate where you switch from PETG to TPU