Two volume controls? (high end DAC w Jadis preamp)

My system is a MarkLevinson 519 file player/DAC driving Mcintosh MC601 mono into B&W 802D3.

it sounds quite good, but I also own a Jadis JPS2, actually the fully balanced version: JPS2S.

Since the Jadis tube preamp has no remote control and has dual volume controls (not ganged), I have some volume level control choices.

I can put the 519 on fixed output (which is essentially full volume), and use Jadis volume and have (maybe?) best sound but lose usability of remote control of volume.

*OR*

Leave Jadis volume controls where they may sound best (maybe about halfway open?), and use remote control & phone app to raise and lower volume on the 519 variable output.
i believe the 519 doesn’t suffer from bit loss that some earlier digital volume controls suffered.
ive also used the 519 as a stand alone direct to amplifiers and it sounds good at all its ranges, to me.

For reference, the Jadis preamp seem to be at unity gain with the volume knobs pointing straight up (halfway open).

Suggestions/comments of any kind related to this system?

Separate question, Is there anything incompatible about using Jadis preamp with Mcintosh solid state MC601 amps?
A short while back a gentleman who already owned some Jadis amps commented that he thought the Jadis preamp was only properly usable with Jadis amps (maybe he was referring impedance matching)?

All opinions are welcome.
thanks