Thank you to the replies and the useful suggestion of mr. Kemper about cabinet usage. A different representation of the profiling of a direct input profile can be useful because now the cabinet is not clear what does represent as a part of the tone. Even a sort of parameter than influence or enhance this kind of profiles can be useful.
I did some try today, even if i miss time and possibility of long session at volume on this period. I did the test i said on my last post, and to be exact a comparation (sorry i can't mic just now, i can share just my impressions) of those 3 situation:
1) tube head - guitar cab
2) tube head - dibox (power output into a mute cabinet) - solid state amp - guitar cab
3) Kemper Amp profile of the amp (made with same dibox and wiring) - solide state amp - guitar cab
The test n° 2 is useful for understanding what part of the loss is due the Kemper and what just in signal conversion. The number one obvioulsy is the parameter for realism. The tone of the test 2, so di box into solid state and no profiling at all, miss a bit of articulation and lively respect the pure all tube situation. Similar but not as good (not bad anyway!), so this is yet a response of where loss start in my tests. An interesting comparation is bethween the test 2 and 3, for an evaluation of the Kemper realism in the di box profiling. A bit of loss even here (so test 2 worst than 1 and test 3 worst than 2) and the tone is darker, even if some equalization can balance that (i'm not 100% convinced about the re equalization of the monitor output without cab). But for my ears anyway a loss can be eard, not a great deal, but yet audible. If the comparison is from the tube amp (1) and the Kemper Amp in solid state and cab (3) the difference is pretty heavy, the tone is close but without colors, colder.
The good part with Kemper side, anyway, is that moving some value into the amp stack tone can be improved, surpassing the test 2 and reducing the lack of articulation and harmonics. I'm not totally sure if i'm moving into a closer tone to the reference amp, but surely adding something like bias and power sagging make the profiled amp "breath" in a tube perspective. Is a sort of backdoor to recover a part of the harmonics missing from the original tone, maybe not exactly same harmonics, but for my ears is surely better than a direct comparison between test 1 and 3. For this reason i said at the start of the post that a sort of a di enhancer focused to underline the tube character will be useful, for play "hotter" tone and compensate the loss of harmonics of the direct input usage (at least the loss it seem to my ears in my test with that amp).