I may be reading the chart wrong, but it seems that if you are a bound psyker (e.g. a Sanctioned Psyker), then there is no reason, if one is already pushing, to not push for the maximum amount possible. The other types of psykers seem to increase their mishap rolls by more if they push for more, but a bound psyker seems to only increase their roll by a flat +10.
Is this correct, is there another downside to going all out that I am not seeing? Or if I am pushing, should I always go for +3 psy rating?