I think your program is ambitious and interesting!
You probably know the Bernard Andres pieces for one instrument and harp. I like the very short pieces in the “Algues” collection, because they provide the chance for a nice balance between the harp and the other instrument. They can be done with violin, oboe, or flute.
Although they would be easy to prepare as encores, I think they are little jewels. There is plenty of room for musical expression.
I’ve not seen them, but I think Bernard Andres has also written some harder pieces for harp and another instrument. You might want to have a look at them.