Quality checks to characterize the high-field magnets before final assembly are usually foreseen when high accuracy is required in the field map. This process may possibly include magnetic field measurements in regions adjacent to the coils, thus different from the target field areas. This technique implies inverse problem approaches to estimate coils deformation parameters, and resulting accuracy may be poor due to ill conditioning of underlying mathematical processing. To counteract such drawback, suited measures are usually taken, but attention is given to the estimating parameters regardless of their use. In this paper, a discussion is presented about characteristics of the relationship between magnetic field and deformation parameters and about the actual accuracy needs when the interest is focused on magnetic field map in target areas rather than on parameters themselves.