I have a bit of free time on my hands - guess I need to mess with the sound system...

Where I am today:
The living room system is a Squeezebox Touch connected via SPDIF/RCA to an external (1st generation Berkeley Audio Alpha) DAC. DAC is connected via balanced cables to ACA mono amps and DIY speakers. The rest of the house is a mix of Touch, Radio, Squeezebox3 and Raspberry Pi with Allo and HiFiBerry HATs - every Raspberry Pi, including the one acting as the LMS is running piCorePlayer.
To make things as easy as possible for my wife and I, the Touch is doing volume control (with the DAC volume control set to 100%) so that we only have to deal with a single remote, and we can manage everything through the Material skin and our home automation system.

While I've never verified this, it was my understanding that the Touch did volume manipulation with the least significant 8 bits - this was fine when all my music was 16-bit since SPDIF can pass 24-bits, but I now have a larger library of Hi-res music.

What I'm looking to do:
* Assemble a very high quality single box digital audio player and integrated DAC with volume control, including both RCA and balanced analog outputs. (My strong preference is for DIY to round out my system and for the performance/cost ratio.)
* Support for 192/24 files and, headroom for higher resolutions.
* It's got to have a high WAF factor - she won't let me stick a stack of boards in the living room.
* Squeezebox client for integration with existing whole-house LMS/Squeezebox system.
* DSP functionality - mostly to get loudness contour (ISO 226) control since a lot of this is lower volume listening.
* It's desirable but not required to include support for HDCD (haven't seen much of that) and MQA decoding.
* It's desirable but not required to include a nice color touchscreen since I think that's a nice touch.

Questions
* As I'm starting this investigation, appreciate any feedback or suggestions, additional requirements that I haven't considered, specific hardware and software suggestions, etc.
* Based on my research, I've been focusing on the Audiophonics Balanced DAC 2xES9038Q2M kit running Moode. Any feedback from those that have built this kit? Are their other high quality integrated player/DAC DIY kits that I should be considering? Has anyone used the DAC board and built this into a box with a high-quality color touchscreen while running Moode?
* Am I correct in assuming that 32-bit DACs with volume control such as the Audiophonics Balanced DAC 2xES9038Q2M will not strip data from 24-bit data files? My assumption is that the Raspberry Pi will pass unaltered 24-bit files to the DAC, and then the software on the Raspberry Pi will directly manipulate the DAC hardware to adjust the digital volume - is that correct? Or are the source files manipulated for volume before being sent out via I2S? I'm assuming that digital volume on the newest hardware will be an improvement compared to what is being done on the Touch.
* I was initially leaning towards an I2S connection, but is it better for me to consider USB between player and DAC, since that could also be 32-bit? I know that this opens up a whole new area of questions but have to ask.
* Any feedback on Moode in general? While all my other systems are running PCP, I'm looking at Moode due to the dsp integration, which includes a loudness contour.
* Does anyone know about DIY kits that integrate MQA decoding, such as the ES9068AS?

Thanks!