My preference is to add a note at the end of the Findagrave citation (copied from the memorial) to describe the discrepancy if the information at Findagrave is incorrect and to note that I requested an edit to the memorial's data. If I receive a message that the data has been corrected, I then remove my note from the citation.
I don't believe that editing the citation from Findagrave will result in a suggestion. However, unless you mark current suggestion as corrected or false, it will remain on the suggestions report as long as the data discrepancy exists.