So are you following the runtimes of the dive plan on the Petrel or following the Petrel's deco schedule entirely? I assume you're using the same deco model for both cut tables and Petrel ?
The tables are cut with multi-deco. I follow the petrel's deco unless I completely disagree with the petrel or the petrel fails. If the petrel fails I can deco out using just my g-shock and the tables.