Is it permissible to shorten and combine prayers for a traveler who intends to stay four days, then return on the fifth day?

Scholars have differed regarding the duration of stay after which a traveler becomes a resident (muqim). The majority of scholars hold that it is four days, while others opine it is twenty-one days. They also differed on whether the days of entry and departure are included in this duration; the majority of scholars believe they are not included, whereas the Hanbalis hold that they are. Accordingly, the intention to stay from Monday to Friday may necessitate completing the prayers (itmam) according to the Hanbalis, thereby negating the concessions of travel, while it permits benefiting from the concessions according to the majority of scholars. The matter is characterized by flexibility due to the absence of an explicit text concerning it.