People have done it in the past, so you might take a look at the following thread. (The topic Title is a clickable link)
Most people who really need this do end up getting purpose built devices because of some significant safety issues. But those can be very expensive. main safety issues are cool
operating smoothly enough in both directions that the glass does not crack
having a “bump stop“ feature so that it doesn’t close on someone’s fingers. Or someone looking out through the window. This is a real hazard. Even though you think people would notice, they don’t always if they are just resting their fingers on the edge or if it’s a child.
handling the situation where the window is partway open and the power goes out and has been restored. Do you want to make sure that the window understands it’s relative position so it doesn’t try to open or closed too far, either of which can shatter the glass.
So… It definitely can be done. It is most often done with purpose built devices. And purpose built devices are probably much more expensive than you thought they would be.
The Firgelli looks possible for “Trapdoor“ type applications like a skylight.
The issue with a casement window that opens out is that a firgelli type actuator will block the window opening, and that complicates things for some people, particularly if they have a window they want a cat to be able to come in and out of. Normally you would position it right at the centerpoint of the vertical frame so that there’s no chance of twisting the frame when you push it. But that’s then cutting the open space in half. Doesn’t usually make any difference with a skylight, but it might with a casement window. Also with a skylight you typically only need to open it two or 3 inches, where people may be looking for a much wider range for a casement window.
Also, there’s the issue of wind force with the casement window which can complicate things if it’s a windy day. Again, that’s not typically an issue for skylights.
So it might work, but I would have definite concerns about potentially cracking the glass.
Finally, there’s the issue of locking the window. If the windows locked and the firgelli was activated, it probably would crack the glass. I don’t know if it’s a window where you would be comfortable leaving it unlocked most of the time.
BTW, while Truth is probably still the most popular brand for this, Olide Auto is a Chinese brand which has had a good reputation for automatic door openers and is now offering some Alexa and Google assistant compatible window openers. This might offer some pretty easy options. You might even be able to swap out a Z wave/Zigbee switch for the Wi-Fi switch they give you once you have it calibrated, but I haven’t looked into that.
You’ll see from the reviews of their door openers that they don’t put a lot of effort into English translations, but the devices seem to be pretty well engineered.
