Contrary to what the manual indicates, it seems that Virus TI (not 2) doesn't implement voice stealing very well if at all. Voice stealing meaning when the oldest notes are stopped prematurely to allow new notes to play. Instead when playing a pad with unison at 5 voices and a slow release and you play too many chords too quickly, some notes will simply not play.
(And I've already brought in osc 2 and reduced the unison to 3 to solve the issue, just pointing out that the behavior is not what I expected.)