Is it possible to replace the Windows shell with Steam to launch to Big Picture faster, and have Explorer.exe load after Steam launches automatically?

I have a Steam Deck which I dual-booted to Windows. What I'm trying to accomplish is a facsimile to "game mode" on Steam OS.

I want to boot to big picture automatically extremely quickly so it functions primarily as a game console first, but then be able to exit to desktop via the menu in Steam.

I know the shell can be switched from explorer.exe to steam as the shell via changing the reg key from:

HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell

to

"C:\Program Files (x86)\Steam\Steam.exe" -bigpicture

What I'm unsure of is if placing a shortcut to explorer.exe in the startup folder will allow me to exit back to the Windows desktop without any hijinx like creating a shortcut to explorer.exe in Steam which has to be launched first.

If this won't work, is there another alternative? I want the process to be as fluid as possible, so the exit to desktop menu item in Steam functions as expected.