I’ve got a 2018 Flare Max, so unsure whether it’s a mk2 or 3.
But, on mine by taking out a spacer in the shock I get 132mm of travel rather than 120mm and since I already run a 140mm Pike I thought there was too little in it to consider a Jeht – so if changing to something longer travel I’d go straight to a Rocket Max.
Before you spend a load of cash though, try a -2 headset. This made a lot of difference to how capable mine is. I’ve also changed to a (reduced travel) Lyrik and the stiffer fork has really helped on the faster/rocky stuff. And if you do swap later, none of these are wasted because when buying from Cotic they’ll happily ‘delete’ any components you don’t want.
If I was buying from new now, I’d probably just go straight to the Rocket Max – weighs barely more than the Flare Max but would be more suited to the riding I now do.