This information applies to the RLX & RLX hybrid.
There is a very prominent bump at the bight (seat crease) in 2C which will interfere with a secure installation of many infant seat bases (as well as other car seats) and also prevent boosters from sitting properly against the vehicle’s seat back in many cases.
The lap belt for 2C is anchored high in the seat crease which can make the lap belt fit poorly on some as it can make the lap belt sit on the belly, rather than on the hip bones as it needs to.
The roof is very low; when sitting in 2C, the head of a 5’1″ adult touches the roof. This means that 2C is not good for most adults, and is also problematic for many forward-facing car seats & high back boosters as they will likely sit too close to the roof and be a driver visibility problem as well (when trying to see out the rear view mirror).
While the RLX was redesigned for 2018, the back seat is identical to the previous models (the stitching lines in the leather are all that changed).