Califs project does not use an SPTM bypass which is why in the demo they only showcased a webassembly tweak. To my best understanding it's similar to what was done with DarkSword, just a more developed environment around it and on newer versions by utilizing a new kernel exploit. The SPTM bypass patched in 27.2 Beta 3 is unrelated to that however and could in theory be combined with Califs Kernel exploit to achieve a full jailbreak (e.g. Dopamine). Note however that this SPTM bypass is allegedly incredibly cursed and it won't be easy to reconstruct it using patchdiffing.