No, because `slowrxd` is running on the RPi4, if I did what you're suggesting there, I'd be sending the I/Q data off elsewhere to be decoded, then sending the decoded audio *back* to the RPi4 to demodulate the SSTV transmission.
Utterly pointless.
This is a headless station. There's no phone. There's no laptop. There's no desktop. There's no monitor. Just a radio, a RPi4, and an Internet connection. It hears a SSTV signal, it decodes it, it slaps it up on the Internet via the [@vk4msl_sstv](https://mastodon.longlandclan.id.au/@vk4msl_sstv ) bot and throws the image up on a website.
Putting a second machine in only moves the problem, because the second machine will be headless like the first.