While it's hard to compare one Revo to the next because of Gap differences...
I do believe .38's fired in .357 chambers do avg around 20-30fps less than they would do in nearly identical .38s...problem being...nearly identical same era, same make, same forcing cone gap etc.
As for case length/recoil...yes I think it matters a bit. like a 10mm pushing the same fps as a .40...there is less of an early pressure spike I believe. Same thing as above though, the .40 fired in a 10mm 20-35 fps less app.
So theoretically, does 9mm have a slightly higher perceived recoil, faster pressure spike then a .38 pushing same fps in same weight lcr? Yes perhaps. Would a .357 pushing the same have even slightly less...
Yes perhaps.
2 LCRs, good handloads, and a Mantix X somehow mounted would be interesting...
But is it enough difference to make a difference, and overcome...price?