Thanks. I should add that I'm NOT using the F1 kit for developer. I've been using the Kodak Flexicolor LU/LORR kit for developer, and the off-the-shelf final rinse. I've been using these with leftover bleach and fix from a Rollei kit, but those solutions (the separate bleach and fix) will soon need replaced. The F2 kit does contain only bleach and fix, and that's exactly what I need.
In any case, it sounds like I should stick to the six-and-a-half minute times, which I'm absolutely fine with.