Continuity is persistence of an action or state; renewal concerns repeated occurrences on new occasions. An imperfect can foreground either or both, depending on context.
AspectPossible implicationRelevant setting
ContinuityObedience persistsImperfect after law
RenewalObedience across many cases“In many matters”
These aspects can coexist. Calling every imperfect merely “present” or “future” would suppress the aspectual nuance being discussed.