Would a RIMs tube in which you recirculate wort thru said tube and back into the mash be harmful to the wort in any manner, in regards to the LODO techniques ??
If you're using silicone hoses to recirculate then yes, most definitely. Silicone's oxygen permeability, especially at mash temps, is just horrendous.
The tube itself is usually made of stainless steel so there's no issue with the tube itself.
I'm curious about the same thing, but, would doing something like using insulation tape on my silicon tubing help a fair bit? Replacing it all with EPDM seems like a lot