Plantaginea does need some sun to put on a show, and that it does with plenty of sun along with Aphrodite which is basically a plantaginea with a big double flower. with out sun Aphrodite flowers will not open. sieboldiana Elegans would maybe flower better with more sun, but you will lose it's pretty blue color.

The more sun the better, and Plantaginea will grow in full sun as long as it's kept watered. Half sun or dappled shade all day would be okay, but more sun is better. It's also a hummingbird magnet, as are most of the fragrant hostas.

Along with sunlight heat is required as well to promote flowers to bloom. You could have dappled shade for a flowering hosta and it will still bloom if it is hot enough in that location.