Both are still 55 h/w of grinding. Worrying about WLB and not keeping your head down would be, "I'm off the clock, no more working on anything related to work in any capacity today".

Prepping for interviews outside of work would still very much count as "grinding" in my opinion.

I was going to say this as well. If you haven't done competitive interviews, it's easy to underestimate how much prep / skill is required.