I like this approach much more than the Certifications, which does not mean that Certifications are useless.
The limitation of certification path's is that you are sometimes left with open questions. The learning packets are big and you need to focus on the certification assessment.
Specially things like Sentinel may be considered as less beneficial to the goal of a specific certification. There is a big potential to get lost and waste planned time, since the impact is low.
With this more narrow approach I am happy to learn more about those "partially left out" topics.
Please add more of those scenarios.
I see potential in: MFA deployments and onboarding scenarios, Phishing resitance scenarios, Enterprise App management and its security aspects, Keyvault exercises and VPN scenarios for hybrid implementations.
Another good story would be the whole DLP stack with data sensitivity labels and the design of compliance scenarios to get out of "your own box". This is a well covered scenario, but has a lot of avenues and approaches to discover.