That makes a lot of sense, thanks for taking a look. An index like you suggest would probably further improve the query. Is that suggestion sidestepping the original problem that production is evaluating the landing_id bit with the partition index and qa is sequence scanning instead?
AND exists (select 1 from t_sap where e.landing_id = t_sap.landing_id)) as rankings;
Based on the difference in row estimate I am attempting an analyze with a higher default_statistic_target (currently 100) to see if that helps.