I have never been comfortable with the treatment of lifted off supports described by Richard. Admittedly, I haven't got both feet in the stirrups on this one or whatever you say in Tx so I am not offering a definitive statement.

The Caesar method handles only the warm up case and refers to the pipe sagging back onto the support. IMO stress range is a 2 way thing. In stress calcs we consider the cold to hot load case. More specifically in calcs we consider the range from the installed position to hot position at the end of the first heat up.

In reality we should really be calculating stress range based on actual cold to actual hot positions and the reverse.
It is easy to show that the installed to first hot position and actual cold - hot - cold positions are not always the same. (Not just for lifted off supports). If the lifted off support has sagged back onto the support when hot, my gut feel is that the worst case stress range would be from the actual sagged hot to actual cold positions. It's been on my good intentions list to try to calculate this but I have never got around to it. The horse won't stand still for long enough.

Being a simple sole, I assume that if a support can be shown to be not required in the hot case, then there is not much reason to have it in the cold case. I do the calcs with the lifted supports removed from the calc. I'd always check to make sure it didn't have a negative affect if it was physically left in.

If the support is requred then I'd look at a reroute or a spring. I seem to use fewer springs that some folk I know, so I don't think the simple approach is having much affect on pipe system cost.

(By "actual" I mean the position adopted after the pipe has settled down after several cycles).

Andrew