HMAC is a widely used crypto-primitive. For example, it may be used to implement authentication schemes with 2FA (HOTP is basically an HMAC). Or used as it is, for a data authentication.
AMM emulator allows to provably calculate the AMM pool state by using the (initial state, list of operations). 1000 operations are executed in less than a 1.5s.
It was almost 5 years since last time I used such low level assembly like Polygon Miden, so it took me some time to get into. After all it was an amazing experience, nothing really bothered me. The tools are well done, no fantom bugs or anything like this.