Took Step 1 last year and got above a 260. I studied very very hard during second year, and studied even harder than that during my step 1 prep. I drank, traveled, and enjoyed the last remnants of true free time (truly free from any responsibilities) and savored every moment of it between M1 and M2. But you gotta do what works for you, if you think you're an exceptionally slow learner then maybe it's a great idea for you to study. If not, 100% of the people I know who scored above 250 enjoyed themselves during that summer, came back rejuvenated and ready to rock for M2 and crushed boards. I tried to read FA, but got through the introduction and gave up.
M2 material requires repetition but more importantly structure. Learning this material on your own from review sources is exceptionally difficult. Frequently, review materials skip understanding for the sake of giving you high yield facts (this of course is because they assume you already understand a concept). There is so much material during M2 that the casual "perusing" you're describing will never yield any realistic pay off, in order for it to pay off (meaning actually remember any of it when the subject comes up again during second year) you need study for it in a very dedicated manner (think an 8 hour day at least). Do a research project that's likely to get published if you must feel like you're doing something, that would give you a much better return for your time investment in the long run.
Tl;dr: Either hit it really really hard and do like 8+ hr days for the entire summer (Heavily advise against this unless you're special), or do nothing at all. Because 1-2 hours a day will yield you nothing, that's not enough time to actually memorize anything for you to see dividends later.