From C-recorders to F-recorders

I played the flute for nearly a decade, so when I picked up the recorder I naturally started with the soprano, as the fingerings are similar. I've since acquired an alto and a tenor. As I get better, there's less music that I can play on the soprano and tenor and more that only works on the alto. All the anecdotes I've read say that good recorder players know how to play both C- and F-recorders. Is there a method for re-wiring my brain and fingers to learn that? Also, why is it the standard to write music for F-recorders in concert key rather than transposing it? Is it blasphemy for me to do some transposing myself, just to ease me into it, and will it come back to bite me if I do?

From C-recorders to F-recorders

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