Update...
Last Saturday being alone on the mountain (without the rest of my family, that it) I carved out a piece of time to pay visit to the boot-fitter where I bought the boots and have the line heat molded.
It took about 20 minutes (liners heated inside the boot, then feet inserted into said boots and buckles closed).
Unfortunately then I had to ski with those boots straight away, no sense in molding the liners and then letting it cool donw inside the car's boot (trunk) for the rest of the day.
Alas I had only my Voelkl RaceTiger skis with me, having not foreseen the need to ski in the ZGGP (ok, I have been naive) soon after the moulding to finish the formation of the feet shape in the liners...
No big deal, both my boots are size 27.5 / 315mm bsl, so I just slipped the boots in the bindings and off I went skiing, a GS-like ski in "light" (at least much lighter than the 9.8 I usually employ) freeride boots...
I had also, the evening before, inserted the little spoiler provided with the boots to further the forward lean of my legs (I felt too upright the last time I used those). All in all, the weird feeling lasted just about the space of two runs, then I forgot I was skiing in freeride boots with tapered and "vibram" equipped soles and skied normally (I mean I felt I was still driving the ski without much troubles). Only a slight nagging thought in the back of my mind was present:"do not fall, release value are not what it is supposed to be, the boot/binding interface might not be set up ideally", but it just lasted a few milliseconds.
Boot felt tight at first, the same pressure points of last time still present (toes feeling cramped) especially the external side of the big toes and the external side of the right foot, particularly near the heel and on the instep) but as time progressed, feet became un-cramped and did not became numb like before, instep feeling too pressured went away as well, only a slight numbness on the external side of the right heel was left.
All in all much improved compare to the miserable day I experienced before (then I had spent the day in the backcountry and by the end of it was spent and had my toes so numb I just wanted to go home and not ski again the next day.
A much different experience from the first day I used the ZGGP where everything felt fine, but it was a much warmer December day, that one, and herein it might lie the difference) even if with still some small points to address.
I had planned to have a custom footbed made during the same visit (comform'able like) but the footbed of my size were out, the only available were the carbon race types, which I deem overkill for a freeride boot , too stiff, wherein was looking for comfort (I use a very old comform'able footbed and transfer it from boot to boot since 1992) and room.
Yes, the idea to transfer my comform'able footbed back and fort from the 9.8 to the ZGGP each time I use one of the two has struck me.
But knowing myself I know that I would, sooner or later, end up in the boot, miles from home, without footbed with said footbed at home in the unused for the day boot.
For the time being I will nevertheless do that. Then we shall see.
Another mod, unrelated to comfort and/or performance though, I would like to attempt is related to the first buckle...I'd like to invert it (handle on the inside) taking example from the new Tour Pro that Tecnica will replace the ZGGP with...need to mull this one over for a while...