[Bug]: Send Calls - Triggering a wallet_sendCalls with 3 tx's takes ~6 seconds until the popup is open and ~10 seconds until something in the UI is shown in FF

**Describe the bug**

Triggering a wallet_sendCalls with 3 FF takes ~6 seconds until the popup is open and ~10 seconds until something in the UI is shown in FF

**Screenshots/Recordings**

https://github.com/user-attachments/assets/b5241dec-43cd-4e6f-b2f3-760fae378c4b

See comparison with a regular Send, using the same wallet

https://github.com/user-attachments/assets/a885f0bc-1f0e-41ea-9f7b-705555dc8df8

**Steps to reproduce**

1. Install MM on Firefox
2. Open test dapp
3. Connect
4. Upgrade your EOA account (if it's not yet upgraded)
5. Trigger a Wallet Send Call with 3 tx
6. See wait time

**Error messages or log output**

```shell

```

**Detection stage**

In production (default)

**Version**

13.2.0

**Build type**

None

**Browser**

Firefox

**Operating system**

Linux

Reproduce the three-transaction wallet_sendCalls flow in MetaMask on Firefox using the linked recordings as the timing reference. Measure the delay before the popup opens and before UI content appears, then trace the relevant request and popup flow; done means the Firefox flow no longer has the reported multi-second delays and remains functional for three transactions.

Written by the indexing model from the issue text.