Firstly, the nominal line level isn't related to full scale. So the consumer line level of -10dBV is not supposed to correspond to dBFS on the digital side. In the old days before the loudness war, a digital playback source was intended to have considerable headroom, something around 12 dB, assuming that a digital recording would produce somewhere around -10dBV when playing back a nominal level of -12 dBFS. This was intended to produce similar playback levels between CD sources, FM sources or cassette sources.
Eventually, the levels have been consolidated into ISO/IEC 61938, which says that the nominal level is 500 mV (-6 dBV), while the maximum level is 2 V (+6 dBV). The maximum level corresponds to full scale on a digital source. There is also a minimal level at 200 mV, which has minor significance; it is intended to mean a minimum practical nominal line level that a device ought to be able to expect. Note that -10dBV is somewhere in between. Take this as a hint that levels are fairly weakly standardised.
Nevertheless, even the weak standard is widely being ignored.
For the discussion, at the very least you should distinguish between nominal and maximum level, as there is a difference of typically 12 dB between the two. If you are talking full scale, it is going to be the maximum level.
Furthermore, when looking at the data sheet of the PCM1794, you must notice that it has current outputs. Hence there is no nominal output voltage with this DAC. It is purely defined by the external circuitry that comes after the DAC. Depending on its design, almost any desired output level can be achieved.