Unfortunately we'll never know what they are really capable of without the structural/material data and simulation from an industry standard solver so I personally can't answer your question. After all its just a wheel spacer anyway
RE Performance Spacers for Porsche cars;
I did a significant amount of work and research on performance wheel spacers back in 2015 (weird I know; to finally manufacture a few dozen then to quit loll). We also squeezed out a lot of weight from them, however, it was simply impossible to cut/extrude them 100% trough. Reason for this was rot/centrifugal and thermal expansion. The way we managed to structurally stabilized the spacer is by leaving some material inside the pockets i.e to keep the pressure points with near-zero displacements. Having them 100% extruded/cut had displacements all over the place, for us anyway.
Obviously some managed it somehow, as shown in your link. I'm feeling like a rookie now I tell ya :/
OT and other findings (secrets loll): The significant factor to get a wheel spacer to work both on the street and track is material and treatment. To my knowledge only heat treated AL7075 alloy will work for performance spacers and I only know of two manufacturers who actually cares 'that much' lolll. Not mentioning names here (both based in Europe). One in fact forge them then machine the final pass to tolerance. As in crazy expansive stuff... for what it is and what it does anyway (and the reason I've quit this spacer game, btw).
Thermal stress is a nightmare and beyond-nightmare on lower AL grades. As they inevitably expand, this
incredible force/energy is directly transferred between the wheel and the lug bolt (nuts, whatever). Meaning if you spirit drive your porsche car or track-it then keep in mind that your lug's torque is roughly 25x more than what the wrench's clicker told you once they are HOT:/ This is obviously sorted with genuine porsche part lug bolts, nothing else works really e.g. those bolts with AL floating R15ball thingy - or those that comes from factory if you prefer.
As meaningless and silly as spacers sounds (other brand/make/china whatever), it still can be done right. Careful selection of lug bolts and regular wheel torque checks is required however.
Wider-the-Better! Lukin better also... love my rear 15mm spacers