if you reach out to alberto i think you will find him responsive and very knowledgeable... obviously he will champion his (excellent) product and he will clearly explain how the audion monos differ from the one chassis stereo model in technical and practical terms
you are experienced at this hobby now, so i am sure that if/when you get an agd amp, you will listen to it on its own first, before coupling with tubed gear in the chain... you may well be surprised you may not want/need add’l ’tubey goodness’, (which certainly comes at a price monetarily, and usually, also sonically, to some degree, while bringing its gains)
i think i have mentioned this in an earlier post... i have been a hard-n-fast die-hard tube gear guy since the 90’s, i have much tube gear and boxes and boxes of so many tubes, but as my streaming journey has progressed since 2020, as the front end has gotten purer and purer, i now am ecstatic about the quality of sound i am getting without a single vacuum tube in the chain - i've come to realize how much of my perceived need for tubes in the chain was palliative in nature, solving for digititis and/or solid state artifacts introduced in the source and amp stages... in this crazy, unpredictable journey i have been on, i would never, never have thought i would be here...