Plate 2 photos
The front decoration could be Qianlong but the bottom looks more like Jiaqing period.
extra photos
extra photos
photo 4 is of plate 3. Sorry
The blue color and decoration looks like Qianlong to me.
Kangxi, in my view. There are two details which vote for this. The underside decoration, and the peonies. The Kangxi peonies on the rim are very typical, shaped like butterflies and having two leaves like tentacles. Even copies of the Kangxi peonies made later in the Qingdynasty do not usually imitate the latter.
That is good information about the peonies shaped like butterflies, I will remember that.