imho (and in my experience) if you run lean for a "longtime" (ie 30 secs - 5mins) you will do damage....... so if you have run it for a looooooooooooooooooooooooooooooong time like 2K miles I would honestly say there is unlikely to be any notable damage
If it was dangerously lean then you really would have seen problems by now. It maybe a tiny bit lean but the ecu "should" be able to compensate. so I think the TMS stance is they will supply a 2.4 inlet BUT will push to sell you a remap...... well what company wouldnt want to sell you more stuff, but the way to get you to buy it isnt to say youre engine will die without it when its more than likely untrue lol
I hope my Lambda switch point slewing theory can work along with slightly chubbier injectors to negate the need for a remap bar a higher rev limit.