@ml8764ag I nudge you not to be so closed minded about the use of a SUT,
I have a Phon’ with a Built in Phonostage that is quite impressive and a Group of individuals that have been demonstrated it and loaned it really like it, but it is preferred with a SUT and Head Amp as a partner, and I agree to this as well, and will say the SUT is the preference for myself.
I also have a MM Only Phon’ that is used with a SUT as the main ancillary and a Head Amp is attached occasionally when I want to have a different flavour to the moment.
My experiences of being auditioned a Hybrid Design Phonostage, is that the built in MC Section, is usually produced from parts that have a similar sonic characteristic and most present with a similar sonic character, albeit a designer may choose where the frequencies are most prominent as a presentation.
A SUT or Head Amp can offer an alternative to a typical presentation.
I have been involved in many comparison demonstrations between SUT’s and Head Amps and have reasonable understanding of how the differences from each during a demonstration are perceived.
From my own experiences undertaken in my listening room, I have deducted that the SUT’s used, will inject a little colour to the presentation, add a hue of tone of richness, to the point with certain SUT's there is undoubtedly a Rich Tone presented.
The Head Amp does not create this perception, the Head Amp's I have been able to use, are more anchored to a Transparent presentation, but can be a tad forceful with a certain frequency.
In a very recent listening demonstration on a system I am quite familiar with, a SUT was brought along by an attendee, from a Brand that was unknown to myself, the impression made was quite a surprise, as it was not expected to stand out for its qualities being presented over the resident SUT used on the system.
If the OP could be successful in arranging a loan of a SUT or Head Amp, to experience the contribution these can make to their replays, there might be enough detected to from the added richness, to extend the trials of using ancillaries with the Phonostage of choice.