I agree with Keith, it really varies by individual. The key is for you and your instructor both to feel like you're ready, and to set limits that allow safe growth opportunities. I didn't do my PPL training through a school...just working one-on-one with an instructor, and studying on my own. That worked very well for me, but I imagine it would be a challenge for some students (and instructors). Having to live with a fixed syllabus and fixed timeline for the major milestones (solo in the pattern, solo XC, checkride, etc.) set by the school would not have worked well for me. 30 hours of solo pattern work before soloing to another airport seems excessive; I did my first solo xc within 5 hours of soloing in the pattern.
A lot of being a safe pilot is about good decision-making. The approach I took, working with my instructor one-on-one and being self-driven (versus syllabus-driven), afforded me the chance to develop those skills. After each lesson, or between lessons, if I wanted to do something (e.g., an xc to a new airport), all I had to do was ask. We'd talk through my reasoning, and if he agreed it was safe, we'd arrange to meet for the sign-off, where he'd thoroughly review my flight planning. On one or two occasions, he gave me a couple of additional factors to consider, asked me to think about it, and to call back if I wanted to pursue it further. In those circumstances, I went with a plan B. It really helped to develop the process I go through every time I plan a flight now that the signoff isn't in the picture. (Except on PE...I just fire up and go!

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It sounds like you plan to move on to the IFR... If so, you might talk to your CFI about doing some preliminary work (dual) that would start you down that road, if you're mostly ready for the checkride and just burning hours required by the school. After all, you need the three hours of simulated instrument flying for the PPL...nothing says you can't do some more. Have your CFI file, and then log some dual xc time in actual IMC. Shoot some approaches. Just make sure it doesn't distract from what you need to do for the PPL...which is virtually all about flying by outside references.