E sector horn for heating

[ProfDrK]

Am I correct in assuming that if I employ an E sector horn (fed by magnetron) for heating a volume of material, it would do as good a job as if I used a pyramidal horn IF there were no ferritic or other material with magnetic susceptability in my target? Proper tuning and isolator are assumed for case 1 and for case 2, no tuning nor isolator are used. The litterature doesn't address such a scenario.