Ok I see.
Question is, I don't have the data bottles yet, so I must still make my investment in containers.
I thought about the decanting too - but I think this can be more practical:
My normal developer dose ("serving") is 250 ml.
I can pour 1 gallon of d76/xtol in 7 squeeze narrow spout bottles, each one 500 ml.
Before capping each of them, I give it a small squeeze and then cap so I get zero oxygen.
For each use, I uncap a bottle, I pour out half of it (250 ml), give it a bigger squeeze, cap, zero oxygen again.
Next time, I empty out the bottle, and after that I open another one.
This way I get zero oxygen and I don't have to do the decanting.
It remains to be seen if after the squeeze, the bottle will suck up air when capped or not.
I'll do some tests.