Viridis can take full sun well. Red Pygmy should have some afternoon shade.

K4

K4, I know for the red dissectum maple they need quite a bit of light to keep the red coloring in the summer. For a green dissectum like Viridis, do they show different colors in the summer in different light conditions? Is leaf tip burn an issue for the green dissectum? So Red Pygmy can do well in partial shade? That is good to know, since the spot I am thinking of for it gets morning sun and then bright filtered shade from tall trees in the afternoon.

Where you are located geographically - rather than hardiness zone - will have more of a bearing on how much sun a JM will tolerate. IME, most green leaved maples, dissectums or not, will easily tolerate pretty much full sun and will develop the best fall color with a lot of sun. But your proposed siting sounds like it would be fine for either cultivar.