Construction feature options in CoolCalc are derived directly from ACCA tables. Not all possible constructions are covered in ACCA tables so if you don't see the exact option you are looking for, selecting a substantially similar option is acceptable.
Newer homes may have better R-values than the available selections from ACCA tables. As R-values increase, the energy efficiency benefit between R-values becomes relatively smaller so using the nearest available R-value is acceptable in most scenarios. CoolCalc does not yet implement custom R-values (MJ8 appendixes 12 and 13), if you believe the construction features of the home are substantially different than the available options in CoolCalc, please follow ACCA procedures in MJ8 appendixes 12 and 13.
You're saying an R-value of 72 in a SIPs roof is not much different from the maximum 35 R in your calculator? Wow. I wonder why I'm doing it. Or using your calculator?
I have an R56 roof, and DOE recs for where I live are R60. I have a R32 wall and DOE recs for my climate zone are R40. If I am BELOW the energy efficiency reccommendation, and I can only enter values that are radically below what I am doing, I am going to wind up with a radically incorrect manual J.
I think this is a deal breaker CoolCalc.
ACCA is a trade organization, and they are focussed on trade networking, trade shows, and monetizing training materials.