You're asking a pretty specific/narrow question that's pretty much off the reservation so no surprise you've got no replies.

It "seems" like "it should work" but physically splicing a different pickup into a harness
designed for a specific pickup ignores the impedance differences and DC resistance between the stock body sensors and the IBeam. With passive pups, as in most electrics, one can swap pups with abandon, and one gets a wide range of tonal differences. With an
active-preamp system as the ES, the likelihood of "swap and it'll work" decreases ...but not to say it wont work. BTW, there is an active and a passive IBeam system, so there's another variable to account for.
You also mention that you're trying to switch out of the ES
body sensors. You can also try switching out of the ES
fingerboard pickup as that is another option for you.
Your answer is to try it for yourself, and then report your findings here.

Edward