That's an interesting result and I hope you post more about the upcoming comparison.
I just acquired a Ceravolo HD 145. It's primary role will be for double stars, but it will see measures of Planetary (Mars is starting to get big fast!), larger open clusters, and some NV work.
But doubles are the key, and with its short focal length (870) my workhorse Leica + Extender only gets me to an effective focal length of 4.9mm (176x). My target would be 3mm. It appears realistic since stacking that combo in a 1.6x Antares barlow demonstrated the Ceravolo optics to be exceptional. Perhaps even better than my old A-P, Takahashi, and Zambuto optics. Better or not, the Ceravolo will eat up the power.
The Nagler 3-6 has a lot of appeal for simplicity. The fly in the ointment is narrow FOV since this scope will be riding on a HalfHitch FTX (no tracking).
The other option would be the Leica and a 4x PowerMate. As noted, that is starting to be a large stack in the focuser. And it gets me back into the swap & configure scenario that the zoom freed me from. OTOH, some swapping seems inevitable due to the scopes short focal length.
I did pick up an excellent Pentax XW 3.5, I'm pretty sure it will pair nicely with my Siebert 1.5x barlow. But I lose the coverage of the zoom (Nagler or Leica options).
FWIW last night I had pretty good seeing, and had the chance to compare the Leica, 6 Ethos, and 3-6 Nagler.
While the view in the 3-6 Zoom was sharp, the 50 degree field is just too small when you are operating above about 200x without tracking IMO. It's quite tolerable, but when you have alternatives, why bother?
Swapping in the Leica + 1.8 barlow gave views at least as sharp, much more field, and I prefer the better eye relief to the Nagler zoom.
The 6 Ethos is a very sharp eyepiece, but I do get eyeball reflections from it, and that makes it pretty distracting to use on bright targets. If I use it at an oblique angle, that's less of an issue, and the massive field makes up for it in part. But it doesn't zoom . . . so I find myself wondering what would happen if I swap in the 7XW, 8 Ethos . . .
So far, my strong preference is to zoom, and if I needed more power than 330x (with Paracorr), I would be looking to a 2x barlow. In your situation, your scope is going to do similar magnifications, so I would want to stick with the Leica, and simply put up with the relatively large powermate or other barlow. Given that I'm already using a Paracorr, that would be more bulk than I want, but the paracorr is not essential, and in your Mak/Newt I'm guessing not needed. There must be a very good quality 3x barlow that would do the trick someplace.