The more I think about this idea the more I'm liking it. Something that's occured to me that hasn't been explicitly mentioned so far in this thread -- how the format will affect the content. If T^5 is written with such looseleaf/binder publication in mind it should affect the way the rules are written and organized, making them become more like wargame rules with brevity, clarity, and conciseness valued primarily (to keep page-count low and prevent chapters (or even paragraphs) spilling onto 'extra' pages).
IMO rpg rules should read like rules -- straightforward unambiguous step by step instructions, with examples where appropriate, and no useless filler. The "conversational" writing style of TNE (and, dare I say it, all too much of GT and T20) and/or the "story" writing-style of many other 'modern' rpgs annoy and frustrate me without end. Rulebooks aren't something to read "for fun," they are a reference tool that should allow you to find exactly what you need quickly and with minimal hassle. CT (and, barring the unfortunate errata, MT) got this right. So, anything that might encourage a return to that 'old-fashioned/wargamerly' style of writing gets my approval.
IMO rpg rules should read like rules -- straightforward unambiguous step by step instructions, with examples where appropriate, and no useless filler. The "conversational" writing style of TNE (and, dare I say it, all too much of GT and T20) and/or the "story" writing-style of many other 'modern' rpgs annoy and frustrate me without end. Rulebooks aren't something to read "for fun," they are a reference tool that should allow you to find exactly what you need quickly and with minimal hassle. CT (and, barring the unfortunate errata, MT) got this right. So, anything that might encourage a return to that 'old-fashioned/wargamerly' style of writing gets my approval.