Do you generally recommend that candidates go 'above and beyond' in preparing for interviews by? In which situations do you recommend this approach or not?

I think going "above and beyond" is a totally subjective thing; it is up to each individual what is above their baseline of preparation for an interview. But - here are a list of things I think are table stakes, that every PM candidate should do at a minimum to prepare:

• Know the company you're interviewing with: their main products/features, how they make money, how they differentiate from competition. If you're interviewing in a division of a very large company (eg. Amazon Logistics or AWS, both parts of Amazon), understand the same thing but for that division.
• Brush up on your past experience and how you speak to the impact you've had. I like to have at least 3-4 examples I can easily pull from, at the top of my memory, so I can quickly and confidently tailor a real story to a question that it makes sense to apply my example to.
• Get clear on what you're looking for in the role you're interviewing for - how you think you might be impactful, what the first 3-6-12 months may look like, etc.
• Get clear on what you're looking for in the interviewers - any red flags to watch out for in how they ask questions or react, what questions you'd want to ask them about the role/company/etc.

I basically recommend these 4 things in every situation, at least.

Depends a lot on what you mean by going 'above and beyond'! I think if you're super excited about a company and spend extra time researching the company and its product, that could help you a lot in interviews. Most companies won't expect you to know the product very well (esp in b2b) and will gear interview questions to be more general, but if you can bring in your knowledge of the product and company, it'll likely be a differentiator.

One should prepare for an interview, especially if its a job that one is very interested in. While preparation is something one should give 100%, one should not over do too. I would rather prepare for questions like what are situations where one went above and beyond in their careers.