Bill,
I have run into this problem myself and I use only the bonus for the axis that applies for profile callout. The only thing that I get concerned over is when you have a surface profile that starts to go past being perpendicular from the alignment axis. Then you should apply the bonus from both width and length. I don't think many softwares will do the calculations for this either.

Duane Wade
CMM/Gage Technician
TeleFlex Automotive - Pedals Division
301 W Ohio St.
Kendallville, In 46755
219-349-1985
dwade@tfxauto.com