Bouncer/swing/chair for higher centile baby…

[Gerbera55]

My just turned 3 month old is very very nearly 9kg which means he will be over the weight limit for the two bouncers we have for him. I was looking at a second hand Nuna Leaf, but from what I can see, Stage 1 with the harness is for babies up to 9kg and then stage 2 is for when they can sit independently but he can’t do that yet.
I’m a bit stuck with where to go, any suggestions for a chair where the harness can be used with a bigger baby?

Baby Bjorn bouncer chair, best baby chair ever

It’s this that I am confused by though! He’s 3 months so can’t sit independently so I couldn’t convert it to the toddler chair but he also couldn’t use the bouncer cause he’s 9kg. Am I understanding that correctly?