This method is incompatible with the autosave feature, and it must be disabled first.
Back up your save files, located under %APPDATA%\Crash Bandicoot(TM) N. Sane Trilogy\, before attempting this.

These titles/shortcuts will open the trilogy into the chosen game while bypassing the Allow Game Launch dialogue box. The title/shortcut launches Command Prompt with the /C parameter, followed by a command that finds Steam's installation path, navigates to that path, and then starts the game through Steam with the map override option.

Credit to BetaM for finding the -overridemap launch parameter.

1. In Steam, in the menu bar, click on the Games > Add a Non-Steam Game to My Library... function to open the Add a Game window
2. In the Add a Game window:
   • Click on the Browse... button to open a File Selection window
   • In the File Selection window:
     • Set the File name value to %COMSPEC%
     • Click on the Open button to make a selection
   • Click on the Add Selected Programs button to create a new library title

• Repeat steps 1 and 2 twice more
• For each cmd title in the library:
  • In Steam, in the Library tab, right-click on the title and from the context menu click on the Properties function to open the Game Properties window
  • In the Game Properties window:
    • Click on the Set Launch Options... button to open the Game Launch Options window
    • In the Game Launch Options window:
      • Set the value to:
        /C FOR /F tokens^=2* %A IN ('REG QUERY HKCU\Software\Valve\Steam /v SteamPath') DO CD/D%B&START "" Steam -applaunch 731490 -om Crash†/L†00_Hub/L†00_Hub
        († being an order from 1-3 for each title)
      • Click on the OK button to save that value
    • Set the first value to the trilogy's game's name, in order of the following:
      • Crash Bandicoot
      • Crash Bandicoot 2: Cortex Strikes Back
      • Crash Bandicoot 3: WARPED
    • Clear the Start In value
    • Click on the Close button to finish editing the title

• In Steam, in the Library tab, right-click on the Crash Bandicoot™ N. Sane Trilogy title and from the context menu click on the Properties function to open the Properties window
• In the Properties window, under the Local Files tab, click on the Browse Local Files button to open the Game Installation Directory
• In the Game Installation Directory, right-click on the CrashBandicootNSaneTrilogy file and from the context menu click on the Create shortcut to do as read (repeat twice more)
• For each shortcut file:
  • Right-click on the shortcut file and from the context menu click on the Properties function to open the Shortcut Properties window
  • In the Shortcut Properties window:
    • In the Shortcut tab:
      • Set the Target value to:
        %COMSPEC% /C FOR /F tokens^=2* %A IN ('REG QUERY HKCU\Software\Valve\Steam /v SteamPath') DO CD/D%B&START "" Steam -applaunch 731490 -om Crash†/L†00_Hub/L†00_Hub
        († being an order from 1-3 for each shortcut)
      • Clear the Start In value
    • In the General tab, set the first value to the trilogy's game's name, in order of the following:
      • Crash Bandicoot
      • Crash Bandicoot 2: Cortex Strikes Back
      • Crash Bandicoot 3: WARPED
    • Click on the OK button to finish editing the shortcut file

By default, these titles/shortcuts will use the Command Prompt icon.

As an alternative, I have extracted the logos from the NST launcher, as well as the memory card icons from the original trilogy, and provided them in both image and icon formats.

Download Link

[drive.google.com]