I’m not 100% sure I understand your test but it’s worth noting ACES is very different than a legacy rec709 workflow. Passing a pure ACES color (e.g. ACES yellow [1, 1, 0] ) through the rec709 ODT isn’t expected to yield a rec709 code value of that color (e.g. Rec708 yellow [1, 1, 0]). You can use the inverse rec709 ODT to find the exact ACES values required to produce a particular display code value.