I don't think it's fair to compare a desktop CPU to the SOC in a pin. Keep in mind the latter is passively cooled which severely limits the power envelope, and on top of that it includes the GPU. Still, in the 10 years since spike 2 was designed, tech has moved on so better options certainly exist nowadays.
The long tail of clips is not due to lag, but simply game events all having their little animation queued up, and the game attempting to show them all to the player. It's a product of GZ just having so much going on. The code could choose to abort all these animations when the ball drains but I guess the programmers want it this way - there's definitely a balance to be found. You can usually press both buttons together to skip.
Regarding earlier comments, I don't think spike 2 is limited in terms of coils or switches as in theory one could simply daisy chain another node board (that's the whole point of the architecture), as they have done with the QR code reader. The limiting factor is more likely the MPU for cases where there is more than one video feed (e.g. second LCD, webcam, etc.) The spike 2 MPU is setup as a daughter board and in theory they could change only the module although that does assume the carrier isn't missing anything they need...