Data Table - Adding/removing columns to/from array doesn't update table

[Async0x42]

I have a simple table template, which based on a vue-router parameter, changes which list configuration / data to load. The config/data register changes properly, but the columns don't force the internal data table columns to change.

Looking in vue-devtools...
Working (referencing the newly updated columns):
columns, columnSelectOptions,

Not working (refering old columns):
cols, columnSelection, regularCols,

<template>
  <q-data-table
    :config="config"
    :columns="list.def.columns"
    :data="list.data"
    @refresh="refresh"
  >
  </q-data-table>
</template>