Can I use the UAS lower anchors that are not designated for the vehicle seating position I have selected for the Foonf convertible car seat?

No. UAS lower anchors have a required standard spacing of 280 mm (11 in.) from center point to center point. In Rear-Facing, using the Rear-Facing UAS Belt to connect to lower anchors that are closer together or farther apart than 11 inches will not allow for a secure installation. In Forward-Facing, Foonf is designed with a Rigid-UAS system and will only be able to connect to lower anchors designated for that vehicle seating position.