As Arion said a +1% award is equivalent to 25tp in old money and 0.05 Q on an attribute. The Q can not display the 0.05 This explains the situations like mine last season where my player achieved the next star while still 5sp away from the Q required. Its just an anomoly because %age is measured/awarded in smaller numbers than SP. Its also why 0.1 appears in player attribute Q which wasn't possible in previous systems.

As an example if you imagine that each attribute has an old style tp progress bar then its possible for 10 attributes to have between 25 and 49tp progress and be awarded 10x1% in each attribute and still have no effect on the attribute Q.

Regarding the 99% achieving 6* then that is probably a rounding issue or even perhaps because they are trying to operate 2 'star systems' i.e a star is achieved by either the %age reached or Q reached, whichever comes first. (But you might want to ignore the 2 systems bit, just popped into my head ) I've had both a player achieving a star at 99% and also, as previously stated, another achieving it 5sp short by Q.