Is volume-based preparation of HEM possible?

Are there recognized protocols for the preparation of HEM using volume (e.g. teaspoons, tablespoons) as opposed to weight? For health workers for whom calculating meal volume and then using a scale is difficult, being able to prepare HEM with measuring spoons would be a real advantage. But there is accuracy lost in the conversion because of the settling of milk powder and sugar, and because even 1/4 teaspoon is not small enough to measure out ingredient quantities without significant rounding. How stringent are the Phase 1 and Phase 2 HEM composition requirements?