Putting a G17 slide on an oem g34 frame is no different than putting a p320 slide on a x5 frame. A g34 is production legal and so is a g17 so if you want to swap frames no problem in the rules with that. That’s how the CZ shadow came to be in the first place, taking the frame of one legal gun and mixing the slide of another legal gun before it became its own oem offering.