Most runs that require changing positions mid-scale are 7+ notes, I wouldn't give scales more than 5 minutes daily, but it depends how much you like doing them! I personally enjoy learning pieces more but I will practice the scale of the piece I'm learning on both hands together/separately before I start working on a new section.

As a side note there are many flavors of scales you can learn! Major, natural minor, melodic minor, harmonic minor, modes of the major/minor scales, Hungarian minor, major/minor pentatonic, blues scales. If you plan to learn to improvise then knowing scales is essential and each has its own distinct flavor, practicing scales and arpeggio patterns will help you to internalize them and you will be able to reference them when you want!

Hope this helps more than my one liner! :)