q-virtual-scroll2.vue

<template>
  <q-virtual-scroll
    style="max-height: 300px; overflow-x: hidden"
    :items-size="size"
    :items-fn="getItems"
    :virtual-scroll-item-size="78"
    separator
  >
    <template v-slot="{ item, index }">
      <some-component :key="index" :index="item.index" :sent="item.sent" />
    </template>
  </q-virtual-scroll>
</template>

<script>
export default {
  data () {
    return {
      size: 100000
    }
  },

  methods: {
    getItems (from, size) {
      const items = []

      for (let i = 0; i < size; i++) {
        items.push({
          index: this.size - from - i,
          sent: Math.random() > 0.5
        })
      }

      // Object.freeze() is optional but good for
      // performance you don't intend to change anything
      // in items later:
      return Object.freeze(items)
    }
  }
}
</script>