What is the general consensus on piping say a triangle tube solo in iron pipe. Basically up the pumps and flow controls and then from that point on would be copper. I haven't seen any done like this. I like iron pipe because it is very sturdy and minimized dissimilar metals near boiler (not entirely since the exchanger on a TT solo is Stainless steel). I also noticed that the Cascade setup is made of iron pipe (a53) I think.
Curious for others opinions and experience.