op - why do you feel it’s time to replace the sf line 2? maybe just send it back to chris j have him check it out retube it?
cj is not balanced (as superb as they are), won’t be able to use balanced out from phono stage
arc ref series excellent, not sure it will significantly outperform a well dialed in sonic frontiers with excellent tubes in place
suggest you don’t fix what isn’t broken, your system is excellent as it is