In the case of families, is it necessary to set up a profile/account for each family member separately?

No, because the inPOL Foreigner Portal allows you to complete applications for all family members. Applications from minor children may be linked to a parent account. 

For your convenience, it remains at your disposal formwhich also allows you to arrange a date for submitting applications in person at the Office. On the scheduled date of the visit, you should appear with the applications generated via the inPOL system. Only applications generated through it will be accepted.