So if you are using a larger cam(s), should you narrow or widen the C/L O2 operating window. Ie lower the top and raise the bottom?

I can answer my own question. Tightened up the O2 window especially the bottom end(dropped the top by 50mv and raised the bottom by same amount) of it and took it out for a ride. If it ever went O/L, I didn't see it.
It stayed in C/L for a 1 hour drive. Engine seemed a smoother, especially at idle, and the BLMs more consistent.