How about Invincibelle 1 or 11 with Bobo

I love the more ‘open’ bloom structure of LQF so it would definitely be on my list for that spot. You could also look at H arborescens ‘Haas Halo’.

This one that frozeBudd mentioned sounds interesting, called "Moonrock". But I guess it will probably depend on availability in your area.

The nursery near me told me they were unimpressed by Bobo. I've been so disappointed by Endless Summer. Huge, green, flowerless shrubs.

With those height constraints, research some of these: Silver Dollar 4-5', Sweet Summer 4', Little Quickfire 3-5', Little Lime 3-5',Strawberry Sundae 4-5', Dharuma 3-5'

Bobo 2.5-3', Pearls n' Pink 3', Wedding Gown 3-4', Magical Flame 3-4' might be actually too short.

Ignore Wedding Gown listed above. Gardenweb is buggy and not letting me modify the comments on any forum.

Some of the dwarf oakleaf hydrangeas do well in east facing sites to zone 5(munchkin, ruby slippers etc etc). They tend to grow wider than tall and are in your size range. I'm in 7A and have ruby slippers in an east facing site with 4-5 hours of morning sun and they have done very well. They bloom early (late may early june), but fade(by early August) for me even with plenty of moisture. The foilage turns some nice shades of burgundy, red, purple in autumn.

Will

In zone 5, oakleaf hydrangeas may be root hardy and yet not bloom reliably. I would research how they do by contacting other persons who already grow them near you (same town) or by observing those that grow in spots that you see while driving. Micro-climates may help with bloomage. For example, I have some whose leaves are evergreen for me.

Are Little Lime really only 3-5' when mature? I have Limelight and they are 8-10' tall (moving them to a more appropriate spot is a future project). I have not had luck with Oakleaf hydrangea and would not want to invest in 4 in them for such a prominent spot. The one I had never bloomed and then died one winter (I just planted a Jet Stream in another spot that gets some protection).

Approximately 3-5'. It should be more compact than its larger "cousin".

All the little limes I have seen have been much more in the 5’ range rather than 3’.

I think the arborescens types would be best for height and appreciate the afternoon shade. I’d worry about some of the paniculatas like little lime if you really want a plant under 5’ long term.

I'm giving up on my endless summer too. I have a bunch of very large planters that have pepper plants in them now, but when they're done I'm going to dig up the endless summer and put it in a pot and bring it inside for part of the winter. If that works, yay! If it kills it, oh well.

I planted a Nantucket Blue in the spring of 2018. I winter protected it and got good bloom results this year. Basically if you live in zone 6 or lower, you have to winter protect it or it will be a foliage only plant. Zone 7 and above, you can get away without winter protecting.

This was my Nantucket Blue at peak bloom this past July in zone 6. I winter protected using the cage method with hay instead of leaves. I feel like hay does a much better job of insulating the shrub than leaves.

I'll see how this shrub does over the next couple of years. If It blooms reliably each year with my current method of winter protection, i'll stick with it since I do love the blooms. If I start running into issues with blooming even with winter protection, I'll consider switching it to a Vanilla Strawberry since I love its pure white flowers. This is one of those things where you need several years to determine it's true performance.

I ended up buying 4 Little Quick Fire for where the 6 Endless Summer are. I am doing few plants so I will have less crowding for the nearby boxwood. I also bought a Firelight that I hope to put near my mailbox with some miscanthus. Thanks for all the help.