From what I saw in his early appearances, he could get hit *once* by a mutant zap, and then use it repeatedly, so he doesn't seem to be a zero sum, but, once he's been 'kickstarted,' a whole new source of whatever energy is sought. (So Neal Sharra for instance could hit him with a single plasma blast, and now there's two people able to shoot those plasma blasts for the next however long.)
That said, I'd have picked an energy-generator like Havok or Stinger or Dragoness or Sunfire or Firestar or whomever (so many options!), but a power-replicator like Synch or Mimic or Bishop works as well.
The whole origin seems new. He's never been a dummy, and PAD added the whole 'gaining new skillsets by sending dupes around the world to learn stuff and then re-absorb them' aspect, but he's never been strictly speaking a *genius* before with a bunch of patents. I don't think he even has a bunch of PHDs, but is more of a dabbler in many disciplines (I don't think it's ever been suggested before that he 'sent his dupes around' for the 7+ years it takes to get a PHD!, but that most of them were gone for a year or two, at most, with a few exceptions that 'got away from him' like the one that settled down, got married and became a preacher!).
Yes, he's worked in Moira's lab as a lab assistant before, but his biggest 'invention' that I remember was a mayonnaise jar that Polaris, Havok and Strong Guy couldn't open (for a practical joke)...
On the other hand, it was neat to see that Layla Miller and their child still exist, and not at all out of character for Jamie to send a dupe to play dad while he fails at the parental / spousal responsibilities... He is his own worst enemy sometimes and, for all his ability to be handling a dozen things at once, sometimes lets things spiral out of control (much like he's got depression), so that's kind of on-brand.
The whole 'working with Reed Richards' thing back in the day seems like a sneaky sort of way to have *a mutant* at least partially be responsible for the unstable molecules that many mutants wear, which, before this, have always been 100% a Reed Richards invention that pretty much everyone in the superhero community has to get from him if they don't want to be naked the first time they burst into flames or turn to mercury or whatever.