As the title suggests, I have a doubt about the computation of the $Q_a$ used to update the delta and the $Q_a$ used to select the next action in the exploitation phase, as shown below (source of pseudocode in Figure 8.9).
In both for loops enumerated in the image with 1 and 2, the $Q_a$ are calculated considering the new state, but while in 1 for each action the active features $F_a$ are calculated, in 2 they aren't. So what are the active features to consider in 2? Are they the same as those in 1? In that case, I could avoid recalculating the $Q_a$ by storing those calculated in 1.