Hi @Artem_Ruzak,
Chrome continues to be the only supported browser on our Synthetics solutions, for a few reasons.
It might be possible to get it to work with other browsers locally, where all dependencies can be installed separately and Synthetics cli simply relays the device configuration to PW's runtime. But is is definitely not going to work on Elastic public locations, where only Chromium dependencies are installed.
As for private locations, since it's possible to extend a container image to install additional packages, it might work. You'll need to customize the images to match PW required dependencies and there might be some issues with additional browsers we are not aware of and technically don't support.