I'm sure more power does deliver more. But the Atom+ stack is delivering plenty for me, as the XS sound better than my 6XX and HE-400se that I own, and other cans that I've owned and sold. Only the Focal Elegia is comparable in my experience and collection.
My point is will something more powerful than an Atom+ stack elicit more dynamics? Yes. But will something like an Atom+ stack "cripple" the XS? Maybe for guys who have a fleet of four-figured price tag amps and cans.
But for someone like me (and the OP, I presume), the XS with an Atom+ stack is a lovely upgrade.
Too often people in this hobby apply their use case and their level of financial and time commitment to EVERYONE else. That's silly.
Yes, you can spend the dough to get a Jot or something with considerably more power than an Atom+ stack. It will sound better. How much better? Up to the ears of the beholder. Also up to the ears of the beholder to make that price-value judgement.
And if you stick with an Atom+ stack or something comparable for a while, does it make you weak sauce and your choice of the XS stupid? I think not.