Hello Saket,
no such UE and/or BAdI is available; however, check the enhancement spot ES_SAPMM07I -- e.g. enhancement point MM07IFZ0_04 is used in form DEFAULT_WERTE, where ISEG-GRUND "Reason for inventory diff." is defaulted for batch-input; this might be the right place to default it for user entry in MI07 as well.
Kind Regards
TomT
