That 72" span limit isn't for SPA, it is something from the newer Ballistic Pattern Association which allows for existing pattern designs up to 72" as well as newly designed models. They are trying to be as inclusive as possible with airplanes like Tipo's and Arrows as well as early turnaround style planes like Aurora's, Jeckyl's, etc. There have been so many threads in the past year talking about both SPA & BPA it is easy to get things confused.

The SPA website has a legal designs list, if it flew prior to the cutoff date it is legal regardless of model size...but I think the model must be "unscaled" although they do allow for a 'fudge factor'- I guess clipping an 80" span King Altair to 72" is considered close enough.