Greek scholarship is doing a better job these days at reading larger units of text and looking for more macro patterns rather than just looking at individual words or phrases.
One of the patterns that has emerged in reading historical narrative material is that the aorist is the default tense, used to begin the narrative. Then, the imperfect is inserted in appropriate places to move the story along. This means that there is something explicitly significant about the tense change, and that emphasis should (I think) be explicit in translations.
"After this, Jesus and his disciples went (ἦλθεν) to the Judean countryside, where he spent (διέτριβεν) time with them and baptized (ἐβάπτιζεν)" (CSB, see also NIV). The narrative begins with an aorist and is followed by two imperfects, although the later two verbs are not translated as imperfective in aspect by the CSB and NIV. (I know, the "imperfect tense" and "imperfective aspect" can be confusing terminology, but these are the terms linguists are settling on.)
διέτριβεν is imperfect, but the simple "spent" is imperfective in meaning, so probably "was spending" is unnecessary (although I would vote for the later).