Tim,
I do a fair number of these certifications for HUD loans.
To be blunt, when you identify the foundation type, you always have the option of saying that it is a foundation type "I", (Other type, not one of the standard types). I don't have the manual with me, but I am 90% this is the correct designation.
You can then "state" that the foundation meets the "force" requirements of the HUD manual and/or local codes.
I will not approve dry stacked piers unless they are used in conjunction with hold-downs (Dead Men), or the perimeter wall can resist the shear. Please note this is in regards to the HUD “permanent foundation requirements”, temporary installations are a different matter.
Also, be aware that even here in North East Ohio, Wind is not always the worst case load. In some areas of very poor soils, I have seen some evidence of dry stacked piers shifting, possibly from minor earthquakes, or just freeze thaw cycles.
Also, last time I looked, the program that HUD passes out to calculate the forces was not updated to the "Newer" seismic values we have in this area.