I bet your seat, footpegs and handlebars would fit a Gen2 just fine.
Yeah, if the price of equipping a Gen1 with a Gen2 engine is the same as buying a whole Gen2, there would have to be some real benefit to the Gen1 frame. I rather doubt there is much difference in weight between the two frames. Gen2 is 593 lbs, Gen1 is 566, both wet weight. The Gen2 engine and exhaust might be responsible for the majority of the weight increase. If that's the case, a Gen1 bike with a Gen2 engine and aftermarket exhaust is going to be 20 lbs heavier than it was with it's Gen1 engine. As you were alluding, it might be splitting hairs to compare a Gen1 with Gen2 engine with a Gen2 with Gen2 engine.
08 MIDNIGHT SAPPHIRE BLUE ZX-14 Now Deceased, will be resurrected, 08 Hayabusa,
2024 ZX-14R bran friggin NEW and 2026 hayabusa!