Can confirm that that seats/harness for Rivals is a little more restrictive than Scooby doo. My wife rides Scooby doo (attendants always give the bar an extra push down for her to squeeze her in) but she couldn’t fit on rivals. Not by much kind you, the clip was less than an inch from clicking in. She’s never had issues with any other ride.
Unhappy wife after I rode it twice forwards and backwards in my own. It’s what I get for marrying a big bootied girl.