Pros + Clean up your audio + Make it easier to hook up speakers and switch between them + Allow BT + Mic input
Cons - Doesn't actually mention headphone power output (saying 600 ohm means nothing. Phones can power 600 ohm, just not well) - Unconfirmed Linux compatibility*
Neutral / Simulated surround will only make the audio worse. Good headphones (which you have) will already allow a wider soundstage, and thus audio placement. DO NOT USE SIMULATED SURROUND IF YOU LIKE QUALITY. / Standard marketing BS
*Unless Creative is playing games with how it works, any DAC should be plug and play on Linux, or really any OS. The DAC chip itself is OS-agnostic, but the USB converter can be an issue depending on how Creative has flashed it.
And basic Mixing would be awesome, because i could switch and multitask better without the need to put down my headphones. Listening to music and still hearing notification sounds from the other device. I don't know. It is awesome. And the real question is "why not".
My PC case is the bequiet dark base 900 pro. It has a QR wireless charging pad on the top. And i am using the front panel connector just 5,5 cm away from the charging pad. I just thought about it. It never occurred to me, that maybe thats the root of my static noise problem. It would make sense in my opinion.
The internal cable for front panel audio can pick up noise from really anything in a computer, I used to have a build where there was a faint hum through my headphones that matched the GPU usage. The heavier the load, the more noticeable the hum.
Have you compared the front panel audio to the audio from your motherboard's rear IO? The rear IO should pick up less crap than the front panel.
Modmic is awesome for what it is. One of those USB sound things that @w.meri linked will do just fine for that.
For notifications, you could just use the headphone jack on your phone to stuff it into a line in on a headphone amp. But honestly, put your phone somewhere else. Phones always produce noise when close to audio stuff. Get a stand for it, put it somewhere visible and make it flash an LED when stuff comes in.