Plant a groundcover instead. Perennials that need to be periodically divided or replaced are not great accompaniments for JM's, as you want to avoid any sort of root disturbance with the tree.

Try Creeping Jenny or a sedum ground cover if you want a little brightness under the maple.

Now, yes. Down the road, probably not :-( Tree roots spread out from the base for quite a distance once the tree is established......a least to the dripline/edge of canopy but usually quite a bit further. And although hostas do not need frequent division, it is sometimes necessary. I'd site these at the far edge of the planting area, if at all. Emp 1 will get to be a big tree in time......20-25' canopy spread.

One GC I really like with JM's is Veronica peduncularis 'Georgia Blue'. It is fully evergreen in my climate, spreads nicely, takes on ruddy tones in colder weather and has a long and very intense bloom season, primarily in late spring (in full bloom in my garden now) but will often repeat throughout the summer if trimmed back lightly after the first flush. Epimediums are also an excellent choice.