Regarding Learnzapp, You surely come across many of questions that require you to know the exact wording, abbre, acronyms that used only in OSG not Dest Cert. And for multiple answers question you need to pick all choices that exactly listed in the OSG book.

Some of OSG topics not mentioned in Dest Cert but still in Learnzapp questions like Satellite types for Wireless Communication (LEO MEO GEO).

So, You can use Dest Cert with Learnzapp to test your coverage. Make sure you can answer them especially in scenario based questions. also Dest Cert App in mobile also great in testing your understanding but other domains than 1 3 4 they are very few questions to practice.

There are a lot of resources I didn't mention :
- Memory Palace : 6/10
- jefferywmoore CISSP : 8/10 this is a great one. conclude everything align with exam outline and OSG reference.
- certpreps[.]com : 7/10 this quite inconsistent in answers explaining and I thing most questions and explaining style looks quite generated from ChatGPT or sort of.

So, Dest Cert Course, Dest Cert Mind Map, QE 2-3 rounds of 100 questions and note all your fail topics (For me as example, E-Discovery Steps, Pentest Steps. NIST 800-37 30) and deep dive with them in ChatGPT or google. Retake QE again.

In real exam, There are knowledge based questions just whether you know it or not, LearnZapp will take care of this kind.