Using the idea that the mines explode upon contact, it can be assumed that includes landing after being in the air via Jump, Dynamite... or another mine(s). Now the question needs to be asked, does your respawn location get updated when you come in contact with the mines and being so close to the track? The answer is NO! That's right, you can use 1 set of mines to go an incredible distance, land on another set of mines and go another incredible distance, all without updating the respawn location. Below is a simple demonstration of this, plus a comparison of respawn locations between the double mega mine jump, and the second set of mines. P.S. I highly doubt this can be practical anywhere, just worth documenting :)

While what Saffron has said about Lap skip is technically correct, it's a little more complicated than that. I'm not saying I know everything about it, but there's more than meets the eye. For example, I noticed that if I respawn right before the checkpoint, it'll respawn me further into the track even if I haven't touched the track. My theory is because the "chunk" that contains the player's current respawn point is despawned at the time of respawn, it uses the next available respawn point that's in a loaded "chunk". This would put a loophole into lap skip in the first place wouldn't it though? I don't think so. I think the checkpoint reloads the "chunks" leading up to and including the respawn point used for lap skip. This knowledge doesn't really help right now though since you'd probably reset anyway since you didn't reach the checkpoint and didn't skip the lap. Again, this is a theory, do not currently take this as fact as the respawning mechanics are just now being tinkered with. And if my theory is correct, that means there's a chance that lap skip is impossible on other tracks because it's not 100% that the finish line reloads at checkpoint, although I think it's highly likely(implying that we can stay out of bounds enough for that). Although if it is that small chance, it kinda would explain the bizarre "forward respawning" cause the previous respawn point is deloaded and the next one is up ahead. I'd need more examples of "forward respawning" to further prove this. All speculation of course, I don't know everything, like I said at the beginning :P