Is taking the initiative to perform a non-extended obligatory act of lower priority than performing the non-extended obligatory act itself, and is it of higher priority than performing an obligatory act of immediately lower priority than it?

Deep and blameworthy questions should be avoided, and this question is fundamentally flawed. A constricted obligation—not an expanded one—does not even conceive of the concept of promptness or lack thereof. A constricted obligation is one for which the Lawgiver has specified a time that does not accommodate any other act of its kind alongside it. As for an expanded obligation, which is the opposite of a constricted one, it is one for which the Lawgiver has specified a time that accommodates it and other acts of its kind alongside it.