Answering my own question 2 years later. The option_name field is not 191 characters in WP. Options field names start with options_ or _options_ for the ACF key field which must also be considered. Sub field names do not need to be verbose because they inherit the name of the parent field as well
'options_'.%parent_name.'_'.$row.'_'.$sub_field_name
Nested repeaters look like
'options_'.%parent_name.'_'.$row.'_'.nested_repeater_name.'_'$row.'_'.$sub_field_name
