What "memorials" for the departed were the Kollyvades Fathers concerned to prohibit on Sundays?
In our Church, for example, funerals cannot be celebrated on Sundays, but the dead are commemorated in all the usual places during the Divine Liturgy. The offering of incense for the departed (our usual "memorial service", roughly equivalent to the EO Trisagion service for the departed) is not only allowed on Sundays, but is always included at Vespers, Midnight Office, and Matins, never being omitted under any circumstances (it is most often also included at the Liturgy, but is not as mandatory). While they are "general" commemorations, most often people will include specific names if observing an anniversary, if newly departed, etc. We regard the commemoration of the dead as the "flip side" of the Sunday commemoration of the Lord's resurrection, and so there's no conflict with the paschal character of Sunday.