A 30 degree diff between the living area and the attic on a hot day is
excellent. It's not unusual for attics to reach 110+ on a hot day,
even with excellent venting. That's well within the capability of the
insulation to handle. Would you be concerned if during the winter the
outside temp was 30 deg below the inside temp? Attic ventilation is
important to keep humidity down and to prevent really high temps, like
140, which are possible with poor ventilation.

So, I wouldn't do a thing. Plus, installing a powered fan raises the
possibility of a considerable amount of air just being pulled in via
the ridge vent and blown out by the fan, effectively short circuiting
what is already there. Also not clear that adding a few more box vents
is going to do much either.