It would be a nice patio tree, but not the best choice for bonsai: as already mentioned, the graft is ugly. Air-layering it above may not be a good option. It's already been discussed, some cultivars root easily, others are more difficult to reproduce, some fare well on their own roots, others are too weak. Without available info on these techniques with this cultivar, you would be taking risks that may not be worth it.
And you can see very few decent laciniated maples as bonsai, even from renown bonsai growers in Japan whereas they've been cultivated for hundreds of years: there must be a reason for that because such trees are a very pretty sight when planted in the ground...