I have the Perixx-Periduo 880 and the 13" Max Carta. Works fine. Only that the touchpad is not very usable as the little black arrow trails slowly on the e-ink screen. But typing with the keyboard makes the letters appear instantly, so for that it works great.
As a stand it also functions very well. Although I like to set the Max on this angle-adjustable stand on a table right in front of me very close-by and use the keyboard laying on my lap:
https://tinyurl.com/yc2w5stb
But that is just a personal preference. It feels easier having my hands down on my lap than holding them in front of me higher up.
The cover of the keyboard can be turned over flat under the keyboard for that.