I'm already tracking how much time I spend studying. I time everything I do in 10 minute chunks and record in a spread sheet what I did every 10 minutes including what type of activity (e.g. reading a book, solving problems, etc) and what area of study.

I usually only track when I spend time actually reading a book or doing problems from a book, but it would probably be more accurate for me to track time I spend doing things like mindmapping or researching fields related to areas I'm interested in, which are more diffuse mode thinking but still are relevant. I also realise I can't spend 24/7 in focused mode thinking and some has to be spent in diffuse mode.

I don't track what I do during my breaks. Usually I'm able to keep working most of the day with minimal breaks or distractions, I might occasionally take a short break of 1 or 2 minutes to get a drink or pat my dog, but most of the time I just keep studying. For this reason I don't think the Pomodoro technique would be useful for me since I think I would end up taking longer breaks than I currently do. Occasionally I take longer breaks usually to Google something that I'm curious about or interested in but most of the time these things that pique my curiosity are not very important and I think I would probably be better off if I could minimise these breaks and spend more time formally studying academic subjects e.g. reading. However I know that I need to spend some amount of time in the diffuse mode of big picture thinking and not spend all day reading. Sometimes these longer breaks are semi related to my study for example I might be researching what fields are related to the ones I'm most interested in (applied mathematics, algorithms, AI etc) or I might be creating a mindmap.