Just last week, Saurik advised the jailbreak community not to hold its breath for an A12(X)-compatible Cydia Substrate, but that doesn’t mean that team unc0ver won’t release a full A12(X)-compatible jailbreak; in fact, the contrary appears to be true.
In the absence of Cydia Substrate on A12(X) platforms and with little or no indication that it’ll ever be updated to support them, hacker and unc0ver lead developer Pwn20wnd embarked on a new challenge – one that involves implementing an improved Substitute for A12(X) handsets specifically while continuing to use Cydia Substrate for tweak injection on pre-A12(X) devices.