Deceased persons information
When you go to the add information button on someone’s details, then scroll down to add other information. There should be the option to add someone’s cause of death and probate/will.
Welcome to the "Community.FamilySearch" Forum.
I am just another 'lowly' User/Patron ...
Just in passing ...
Short Answer: There ALREADY is such an option ... one CAN create a "Custom Fact" ... eg. "Cause of Death".
I do that often ...
ie. "Other Information" Section; and, select "Add Information"; then, go down to "Facts"; then, select "Custom Fact"
One can create whatever "Fact", that one wants (eg. "Cause of Death"; "Will"; whatever one wants.
Such is very EASY ...
I hope, that this may help/assist, somewhat.