Help: Devore O/96 Integrated Amp + DAC suggestion

Hello Devore O/96 owners.

I was very fortunate to be able to purchase a set of O/96s earlier this year, and I'm trying to build out the rest of my system to truly complement these speakers the way they deserve.  I've read many of the posts and reviews across the standard sites and forums, and, while I've found some great information, I could really use some custom opinions based on your experience.  I greatly appreciate any and all thoughts, and my apologies for the long winded setup, but I want to be as specific as possible

I'm all digital via Tidal and FLAC through Audirvana+, and my system currently consists of an Audio Note Oto SE Signature with an Arcam IRDAC and Zu Audio Mission MK1 cables throughout.  My room is approximately 14x22ft. with 12ft. ceilings.

When I'd originally heard the O's in the store, they were driven by a Nagra Classic w/ Nagra DAC.  The sound was literally the most engaging thing I've ever heard...It was electric, punch-you-in-the-gut amazing and had warmth and depth into the music.  The drum reproduction and snap alone had me, and, while I had no intention of spending that much on speakers, after hearing them, I couldn't not buy them.

Bringing them home, I'd originally paired them with a Naim Nait 5i as a holdover from my original Neat Acoustics system, and it was a poor fit.  The sound was incredibly flat...It felt as though the musicians could not have been further away from my listening room.  After reading Rafe's review in Part-Time Audiophile and his thoughts on the AN OTO SE as a match, the fates aligned and I received an incredible deal on a used Signature version.  After plugging into the system, the sound instantly became more engaging.  A richness is present in both the voices and the strings that was missing, and I would say there is definitely more in the way of dynamics.  That said, I feel like (1) I'm still missing significant drum dynamics/snap, (2) when volume increases to approx noon, the sound almost flattens (pushing a 10 w amp too far?), and (3) in complex pieces - orchestral and rock, there is a bit of muddling.

I have a $5k budget for tweaking/replacing, and I'm a huge proponent of used components.  Ideally, with consideration for both space and the budget, I'd like to stay with an integrated amp.  My targeted questions would be:

(1) Is the AN OTO SE Sig sufficient and the DAC the culprit, and, if so, which DAC makes the most sense to achieve what I'm looking for.  Would a AN 3.1, Lampizator, or Border Patrol be the "final" piece? 

(2) While I like the AN, would I be better off replacing both the amp and DAC, and what would marry well? LM 518ia or 508ia/Leben/Shindo Appetite, etc. with one of the above? (several articles on amps with O/96, but none I've seen on amp + dac synergy)

Unfortunately, while Chicago has a tremendous amount of great shops, there's nowhere to listen to any of the aforementioned brands, so I'm heavily reliant on outside opinion.

Again, thank you for taking the time to read this and for your thoughts and consideration.