Regardless of use permission being assigned or not, you can still open the bank. (does it matter if I am admin? am not sure).

Setting default limit to items, is ignored.

{
  "explosive.timed": {
    "enabled": true,
    "minimum": 0,
    "maximum": 0
  }
}

-

{
  "Settings": {
    "allowSafeZone": true,
    "boxes": {
      "bank.48": "assets/prefabs/deployable/woodenbox/woodbox_deployed.prefab",
      "bank.30": "assets/prefabs/deployable/woodenbox/woodbox_deployed.prefab",
      "bank.18": "assets/prefabs/deployable/woodenbox/woodbox_deployed.prefab"
    },
    "cooldownMinutes": 0,
    "defaultBox": "assets/prefabs/deployable/woodenbox/woodbox_deployed.prefab",
    "defaultSlots": 6,
    "keyring": true,
    "NPCBankersOnly": false,
    "NPCIDs": [],
    "radiationMax": 1,
    "slots": {
      "bank.48": 48,
      "bank.30": 30,
      "bank.18": 18
    }
  },
  "VERSION": "1.0.55"
}