Just to clarify, the C-Var loudness controls that Mc used in the past beginning with the C32 operate independently of volume setting. Not like the system Yamaha used where one affected the other.
In design and purpose, the MQ112 is really a playback EQ despite how it's labeled. I don't think anybody is going to buy it with the expectation of it being a serious room correction tool.
True, the later preamps' variable loudness was not connected to the Volume (pot) and had to be varied manually, but still better than a simple on/off (such as one would program into a DSP) or none at all.
I know, separates are what many prefer, but I would strongly prefer a preamp with a built-in DSP (integral MEN-220), a loudness-compensation curve preset in that DSP, of course if you have a DSP you also might as well put the D/A converter in there, streaming, at least one Phono preamp, skip the meters and fiddly knobs and a proper app for control of my music from my tablet or phone in addition to a remote (hopefully an all-in-one for all McIntosh gear). As a playback EQ that too can be programmed into a DSP, one I use has many inputs and outputs so that a phono input (for example) or tape input, or tuner, can each be EQ'ed as a separate device on its way to the preamp, or each can simply have its own program that I can select from my tablet when I switch source.
I do get it that many people like the multiple pieces of discreet equipment, with many gleaming knobs and backlit lettering, people like glowing tube filaments behind glass, getting up every 20 minutes to flip and clean their LPs, much like the "butt for every seat" auto-industry motto McIntosh wouldn't build these devices if their Marketing Department hadn't identified the buyers, their price threshold, the features and performance expected etc. to make it worth the development cost. Much like the quote I've read multiple times about why McIntosh still builds tube gear: because people still buy it. You don't have to leave the AK forums to find those who are restoring and using 8-Track players either, we all have enjoyment of our systems beyond the science and technology of 2023 and that is part of the beauty and diversity of this hobby, ... my original point still stands as "I don't understand", I don't get it, but since many many others do there is obviously something to it (and money to be made).