Author here. Did you miss the part where users can load arbitrary programs into the "new custom TPM"? If we can do that, solving all use cases for all users is very easy: just write the appropriate program whenever a new use case pops up. This is not supporting a subset of current users, this is supporting all users. Every last one of them.
Believe me, given the current complexity of the TPM 2.0 interface, writing a custom program for any single use case is not any harder than wading through the current TPM documentation. Given suitable crypto libraries I'm guessing it's quite a bit easier in most cases.
> However, there's no Tillitis chip in my laptop or my desktop
Yeah, that's the thing with new approaches: they're new. Now if someone made an HSM with the same pinout as a discrete TPM, with a DICE-aware approach under the hood, you could plug it on your motherboard today.