This is so good and important to show that these identity schemes are more about surveillance than security, as the security guarantees are limited and insufficient for any long period of time. An additional approach I might recommend for exploration would be to find the "offline mode," where it would have to re-use IVs and challenges over a short window when the app can't validate against the back end service. Other similar schemes I have seen implemented a single-use-key as a re-used limited-use-key to enable that use case.
The card he tested was apparently live in production, but one of the main vulnerabilities in protocols like these is in the 'personalization' stage of the setup, where each card gets a set of default 'provisioning keys,' which are used to register the card and get unique user keys for it. A sample of unpersonalized blanks would yield that, and the costs associated with mitigating this with batch specific keys for provisioning is typically too much complexity.
There may be a DoS vulnerability in some card schemes where you can use 'torn' NFC connections to get the key and transaction counter on the card applet to increment and desynchronize from the counter recorded on the server, bricking the card - or potentially many en masse with some SDR equipment.
Given the physical user enrollment costs, there are some basic impossibilities in these protocols that will always reduce their security to a set of trade-offs that depend on economics and obscurity. Security research like this acts as a check on the efficacy of totalitarian controls like digital id, and it is important work to continually demonstrate that there are risks and costs to the regimes that impose them. I am very grateful this researcher has done work to discredit this scheme.