Suppletive (?) tonal alternations in Munken

The Munken dialect of Mungbam (ISO mij; Benue-Congo, Cameroon) employs tone lexically and gramatically, contrasting four level tones as well as contours. Noun stems undergo tonal alternations conditioned by the tone of a following possessive pronoun. For some of these alternations it is not obvious that they represent a phonetically natural allophonic process. Furthermore, similar alternations are not observed outside of the possessive construction. If the alternation is suppletive, then Munken would represent a case of phonologically conditioned suppletive allomorphy (PCSA). Tonally conditioned PCSA is only rarely reported, and until now not for any African language.