Maybe not "perfect" but another alternative for an emergency jack:
I may be paranoid but for most of the scissors jacks I've looked at, I worry about them buckling or breaking, or the screw binding or stripping, or the small contact patch sinking into the ground. The Porsche jack in the original post looks pretty good but it's hard to come by in Canada and usually quite expensive if you find one (and some of my concerns still apply to it).
I carry both a small electric air pump and a bicycle hand pump as a backup, to inflate a tire repaired with a plug kit I also carry. I wondered if a suitable pneumatic jack existed and found this one from Vevor:
VEVOR Pneumatic Jack, 2 Ton/4400 LBS Air Bag Jack, Triple Bag Air Jack for Vehicle, Extremely Fast Lifting Action, Max Height 11.8"/300 mm, Compact Size, Short Handle | VEVOR US
The valve assembly has an air tool quick connector but I needed to attach a tire pump. I realised I didn't need separate inlet and outlet valves and even the safety relief valve wasn't really needed in this situation. I removed the hose fitting from the valve assembly and found it had a standard ¼" MNPT thread, so I attached it to a female to female coupling and a tank "snifter" valve.
The two handles that came with the jack aren't needed either. You'll have to get down on your hands and knees to position the jack and from there it's easy to move it by gripping the rubber ring bladder.
In this minimal form, the jack fits nicely in the Model 3's subtrunk.
In order to make it easier to position, I replaced the screw holding the rubber support puck with an M8-1.25X16mm hex cap screw, which I drilled and tapped to hold a rubber foot peg for the car's jack point locator hole. I also cut a slot in the screw head to allow it to be tightened with a large flat screwdriver, since the size of the hole in the puck wouldn't allow a hex socket to be used.
The jack is pretty easy to use, requiring about 50-60 psi to raise the tire off the ground. The jack is lowered by pressing the valve stem, just as you would to deflate a tire.
Drawbacks of this jack are that it's fairly large compared to a compact scissors jack and it's quite heavy, at about 27 lbs. (12.25 kg).