OM,That is why I said generally. Automotive and gases are generally using sae in brass and hydraulics generally use jic in steel. There are sae in steel and jic in brass, but is far less common.
Wearing out or leaking from flared fittings with the dual seat are 99 percent of the time from either over tightening (more than hand tight and a quarter turn) or from using a sealant on the flare. If it has a seal, flare or icing do not use tape.
I agree with you and I understand what you were getting at. I will be using 37 degree JIC fittings with dual seat ss hose fittings (in the 1/2" (8) size). I will head your advice about not over tightening.
GH