A different interpretation of the Code is currently implemented in CAESAR II - A1 is not part of the allowed limits for what we call sustained stress.
If you wish to include A1 in CAESAR II's (SUS) load case, a thermal case must be included. For example, rather than running W+P1(SUS), specify W+P1+T2(SUS) where A1 for T2 is set to the value you want to use. The trick is that you do not want any thermal strain from T2 in the weight plus pressure analysis. To accomplish this, set T2 to a value very close (but not equal to) ambient temperature, or, use a very small scalar multiplier with that T2; e.g. W+P1+0.0001T2(SUS).
I hope this is not too confusing.
Because of your post, we are re-evaluating our position on the application of A1 in "(SUS)" case for ISO 14692. Thank you.