Do your own research. I'm sure there was a good reason why Rob didn't implement it in his design.

Why is it funny? USB-C creates a huge amount of RF interference and can seriously affect Zigbee networks.

USB-C is inherently noisy. Be careful what you wish for...

It's deja vu all over again...

The 1A is perfectly good for the Qutest. The manual says it requires a minimum of 1A and the Shanti output is rated at 1.2A. I have been using it that way for some while now as the 3A is powering my Pi4. If it just to power the Qutest, then either will be fine.

Add an inline switch on the DC side for a couple of bucks. The best place to find them is a Pi shop...

That would be 2Qute/2

I think your guess of 5-10% is very much on the low side. Perhaps you haven't factored in the benefits of swapping to a spare set of charged batteries to double the run time.

What improvements are you expecting in Qutest 2?

Nature already did... A cupped hand gently pushing the ear forward is most effective. Not much use for head-fiers though.

The Hugo 2 is powered by it's batteries and they filter out any noise introduced b y the PSU.

There is a very good one just a short distance down river from Chord HQ

The simplest way is to get an inline switch. Best place to look is the Raspberry Pi suppliers, but their current models use USB-C, so make sure you get the older version. This would do the trick.

The voltage is important. The Qutest will only draw the amps it requires...

You could look at this another way. Chord made their name with high end power amplifiers. The move into head-fi has been relatively recent in their history. It all started with the Chord Hugo. This was not their core expertise and was designed for them by Rob Watts. The success of this project...