Several ISTA Procedures and Projects call for compression testing and compression conditioning. The formulas to calculate the test load during these test methods include a value for stack height. An example of such a formula - this one shown in several procedures and is for an Apply and Hold testing using a compression test system - is:
Wt x (S-1) x F
Where Wt is the weight of the packaged-product
S is the number of packaged-products in a stack and
F is the compensating factor
If nothing is to be stacked on top of the packaged-product at any time, that would mean the S value is "1". Plugging that into the formula above, your test load would calculate to zero, therefore no compression test would be required.