Burning/breaking in new equipment?

You have some excellent components on their way

Treat it like the Grateful Dead said to do with a Love Light - turn it on and Leave it on

a low volume will simply increase the time for the active devices and mechanical parts (speaker cones) to burn in - don't worry about it, just let it run all week or so

it will sound very good to you out of the box

and... it is known to cognitive scientists that you will "burn in" - your perception will accommodate to the sound over time

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two other things you will eventually be concerned with:

room treatments

source material (e.g. some CDs sound a lot better than others, so you'll want to track down the best masterings of an album) -- tho you don't say how you will feed your DAC

Excellent choice. Solid state will not need much if any break-in at all. Warm up thoroughly and good to go. Cables are wires and they dont wear. They may oxidize or corrode after about 50 years depending on humidity and salt in the air. Speaker woofers would definitely benefit from a good loud session (workout) for a few hours. Apart from that you are good to go.

I believe Benchmark sell Canare starquad XLR - so you have the best interconnect cables on the market (from a scientific or engineering perspective - as you can spend as much as a good car on cables if you choose to believe any of the hype)

Transistor gear sounds best when left on 24/7. Tube gear sounds best after being on for an hour +. New speakers benefit from being used for several hours. Wire does not require a break-in period (contrary to popular misbelief). Any CD player with digital outputs will be fine with any DAC (no need for an expensive transport). All digital outputs are "bit perfect" - they will all sound the same (contrary to popular misbelief). This is digital's advantage over analog! I speak from 40+ years experience (I listen to both analog (LP's and RTR) and digital (CD's, SACD's and DVD A's).

All very good advise. I'll add that during the hours you aren't or can't play music, leave your components powered up to continue burn-in.

You don't say what your source will be, but play dynamic music that will cover the entire frequency spectrum. There are also CD's or downloads containing test tones and frequency sweeps for burn-in and setting up a system.

Well done. I also agree with the attitude that gear should be neutral, accurate etc. These electronics are just about as good as it gets, irrespective of price, and irrespective of what snake oil sellers and the voodoo priests on Audiogon may say. The electronics exceed human hearing acuity by a pretty wide margin, and have no sonic signature of themselves at all. Since they are also exceptionaly well built, they may last you a life time. You have been very well advised, and that includes the cables.
So I am bit surprised by your concern about burning in. The speakers may need a few hours, but that is all. And if electronics need warming up, in my book that counts as defective design. For the same reason, I would simply turn them off once you have finished. There is already too much waste of energy on the planet. In fact, leaving them on will reduce their longevity (electrolytic capacitors in particular do not like heat).
The only component with a sonic signature will be the speakers. Even the best speakers are very imperfect compared to electronics. I take it you have auditioned those and like them. However, if you will ever consider upgrading anything, look at the speakers, because there may well be room for improvement in that area (at a price). Think of something like the Harbeth M40.2 (provided the room is big enough). But stay away from changing the electronics.
Finally, as others have said as well, look into the in-room response of the speakers. The room is the elephant in the room. Above the so-called Schroeder frequency rooms are plagued by reflections that may give an overbright and fatiguing sound, but that you can damp with carpets, book cases or more techno stuff. Below the Schroeder frequency, this will not work and you have so called room modes (low frequency resonance peaks at the room’s dimensions making for a boomy woolly bass). You may need bass traps to cure that, or room equalization. A first step would be to measure the in-room response with the REW software.
But first, just enjoy.