with CFE 223's greater temperature stability.
Ha! I got a chuckle from that. Don't know where you read anything positive about CFE223 and temp stability, but it's cause to doubt that source. It's one of the most temp sensitive choices you could make, in my experience. TAC is a similar burn rate but much more stable, for example.
Trying to stick with one powder for multiple cartridges is a common new reloader mistake. You've already acknowledged you'll need more than one pound of powder to use all your primers anyway; you might as well choose one ideal powder for 223 and one for 30/30, without them needing to be the same. Burleyboy's suggestion above is good.
I think you might be a bit optimistic in 223 bullet weights as well, but some of these other guys spend more time with 1:12 twists. From the last one I had in that twist rate, I had much better results in the 50-55gr range or lighter.
