well it depends on the person's strengths and weakness for reading to make a strategy. For me personally I don't like huge reading passages. So when I see multiple long reading passages I start reading and make a small 1 sentence summary for each paragraph writing important things such as people's names, chemicals or theories. I do it for every paragraph and it helps make it more simple instead of reading the whole passage because it works like a road map for me. When I go to the questions I can usually answer the generalized questions first. Then use my road map to find the specific questions or the ones I couldn't remember off the top of my head .
In terms of time, making mini summaries of each paragraph helps me stay focus so I cut down the time of having to read the same paragraphs over cause I forgot what the other paragraphs were talking about and it has proved to be helpful in reducing the time of going back and trying to remember where in the passage the answer is. So in general my time has been good. usually takes about 6-7 min per passage. Never had problems with time once I got the process going