How to center vuetify v-flex boxes while maintaining column sizes?

Question

Vue.js

Do not throw stones, I have been sitting on bootstrap all my life and never thought that I would encounter such a problem.
One of the markup options:

<v-container grid-list-xl text-xs-center>
      <v-layout wrap>
        <v-flex xs4 mx-auto></v-flex>
        <v-flex xs4 mx-auto></v-flex>
        <v-flex xs4 mx-auto></v-flex>
     ...

In general, as I just didn’t pervert, I did column and justify-center and the devil knows what else, until I just fell to crutches with a fixed size. How to center all blocks in the layout so that the size fits 4 columns or 6 or 5?