First off, looking at those USB dongles, you might have to worry about heat and overheating. When I was researching these dongles, the biggest problem was that the smaller ones would overheat and stop working periodically - especially on 5 Ghz.
Also, before buying anything, I’d like you to do some tests at home first. I really don’t want you to have to spend anything if possible.
If you are using Roon via ethernet, try it with different ethernet cables and different switches/routers that you may have lying around. In the past, I’d get different sound from different devices and cables. I’ve made a couple of changes and now all routers, switches, cables, or use of LPS vs. stock switching power supplies make absolutely zero difference. They all sound identical, as they should be. My Cat5e, 6, 6a S/STP and all network devices and connections sound identical. I can play music off the buffer by pulling out the ethernet cable and it sounds identical. Although, the buffer doesn’t last too long. Nonetheless, ethernet cables make no difference now.
Either by yourself or get someone do that swapping test. If you don’t hear any difference, then everything is working perfectly as should be. If you’re also at the same place where the networking system doesn’t matter, then we can have a better reference and comparison with the following:
When I use MPD with flash drives or Roon with Wifi adapters, I find there is the appearance of more depth when switching over. It sounds more exciting. The soundstage moves up. With ethernet and Roon, I find the soundstage moves back and can initially sound boring. Just read the reviews of Hifi-Advice on BDP-3 and Absolute Sound’s review of BDP-2 plus additional notes. There’s another review that echoes something similar. Most people seem to like the thumb drives as being more open sounding and resolving in comparison to NAS playback. Is that actually the case that the flash drive is more correct or resolving, or is the flash drive more coloured with hash which gives a false sense of resolution that supposedly every reviewer seems to prefer? It’s a conundrum for sure that I’ve struggled to answer and have flip flopped many times depending on the mood or day of listening.
However, there is something about the ethernet sound that still sounds appealing and right in its own way. It actually may be better suited in long term. With ethernet, I find the sound more smoother and relaxed. Vocals sound very smooth and ‘continuous’ on etherent - lack of hash perhaps? Although, depending on day of listening, track, and mood, it can sometimes feel as if the ethernet is veiled. Although, that hasn’t happened since my networking side became immune.
I can’t say objectively that one is better than the other as I don’t have measurements or know what might be causing the difference. Is it difference in noise between these connections or the difference in power consumption or the difference in activity and resource consumption or combination of things…I’m not sure.
Lastly, I will say that while the ethernet has sometimes sounded boring or not having enough drive in the past, it has never fatigued me or hurt my ears, no matter how long I’ve listened. The same can’t be said about playback from flash drives in MPD or USB wifi adapter with Roon. Is this because ethernet playback is dulling the sound and thus hiding flaws, and the USB equipment is not hiding anything and letting all the nastyness that is on the recording on the recording through? Or is it that the noise of these USB devices are always adding noise, but at times it can be too much with certain tracks?
Last week I had brought my BDP-1 into my bigger system (20 x 60 feet room) where you can really hear the sense of space change. While all these methods sounded slightly sounded different and if one judges the sound based on things like bass response or soundstage, you may get one answer, but if you listen by another criteria such as human voice and what sounds more correct or real, then you may get another response. I also wanted to give Jitterbugs another try and I did like it and felt they took out the edge/zing and brightness. However, ethernet is the absolute best for addressing that. I have the same experience on my nearfield setup (Amphions + Audeze). Butter smooth with ethernet.
I hope that gives more perspective, even if it doesn’t address your query directly. Make use of the things you may have at home and experiment first before spending a single cent. Try the experiment I wrote above first.