“For the best result, it sounds like I need to figure out a way to hardwire (I think that’s the correct term) the streamer to my modem.”
That’s correct. Especially if you’re going to drop $$$$ on a high end streamer like Aries G2. Don’t get discouraged, it’s doable with a mesh network extenders. Just go to Amazon and search for 2-Pack which includes 1 Router (hardwired to your modem) & 1 Satellite (hardwired to your streamer).
This would be a first step to high quality streaming. Even your Node will improve with wired network.