Or can you place certain indoors furniture outdoors as well? Cos creates and stools would be perfect here... Other than that... The market place in Revenant's Toll has a lot of nice furniture I'd like to set up near Retainers, armor and weapon stands particularly.
Also, sadface that estate Retainers don't offer a discount. Just have them take 5% off the asking price when you go to them in person and remove the 5% sales tax from estate sales. Simple and effective, only other change would be to have the Market Board display a Retainers location if they're on an estate (assuming it doesn't already, have not checked).
Would a new exterior fixture be possible? Lawns would be nice as an easy way to change up the garden. Could have inbuilt paths, I really regret trying to make a stone path work on large/medium sized gardens... Takes up far too much space and in my opinion just looked bad in general. A lawn fixture could easily remedy this though. You could have various styles and various patterns of paving/decking.
Also ponds. Bigger ponds and ponds with fish. Make it happen. We got some eastern furniture this update, I'd quite like an eastern garden as well... Proper cherry blossoms would be nice, rather than using something that requires 12 potent poisoning potions to create...