With a large program, a WebUSB error triggers "Great coding skills!" instead of "micro:bit Connection failed..."

Describe the bug

Arising from support ticket https://support.microbit.org/helpdesk/tickets/88603 (private)

When the current project is too big for V1, it is good that a direct download to a V2 just works without showing the Great coding skills! dialogue

But a WebUSB error leads to the Great coding skills! dialogue instead of micro:bit Connection failed...

Clicking Download for V2 only leads to micro:bit Connection failed..., but after the connection is fixed, it saves a hex file instead of proceeding with the direct download.

By the way, when Great coding skills! is showing, switching tabs or refreshing the page triggers micro:bit Connection failed... to appear.

Tested in v7 and beta.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://makecode.microbit.org/_7vzdxx6H7FL0
2. Connect V2 with USB only
3. Click Download
4. Program is transferred without an error dialogue
5. Connect battery power
6. Reconnect USB a few times until the Download button keeps pulsing
7. Click Download
8. See Great coding skills!

Expected behavior

Is it possible to do micro:bit Connection failed... before deciding to show Great coding skills!?

Can Download for V2 only ultimately lead to to direct transfer or saving a file depending on how it was started?

Screenshots

Great coding skills!

micro:bit Connection failed...

micro:bit version (please complete the following information):
not hardware related ]

Desktop (please complete the following information):

• OS: [e.g. iOS] Windows
• Browser [e.g. chrome, safari] Chrome
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.