Third-party launcher: game killed by Vanguard when spawning mod-tools.exe directly (self-signed cert)

[AmineElBeqqali]

Hi, I'm building a personal launcher (no distribution) that invokes mod-tools.exe runoverlay
directly from an Electron app.

Current status:

• Re-signed cslol-dll.dll + mod-tools.exe with a self-signed cert (added to local trusted root)
• C0000229 is gone — AH Result: 00000000, WAD redirection works in logs
• But when the game launches through the Riot Client, the following happens:

Behavior:

1. mkoverlay completes successfully, WAD files written correctly
2. runoverlay starts — logs "Waiting for league match to start" then "Found League"
3. Game launches then immediately quits (no error shown)
4. Clicking Reconnect loads the game successfully but with NO skins — overlay is bypassed

Without the overlay running, Reconnect works fine — so the crash is caused by the overlay.
The delegation workaround (launching official cslol-manager.exe and hiding its window)
works perfectly with the original LeagueToolkit signature.

Questions:

1. Is the game quitting immediately even a Vanguard issue, or could it be something else
   entirely (wrong arguments, timing, DLL state, etc.)? This is my main uncertainty — I'm
   assuming Vanguard but I have no way to confirm.
2. Is Vanguard compatibility tied specifically to the LeagueToolkit certificate? Would a
   publicly-trusted CA cert (e.g. Certum OV) fix the immediate game quit?
3. On Reconnect, does the game bypass the overlay because mod-tools already exited after
   the first crash?
4. Is there a supported path for a personal-use launcher to call runoverlay directly, or
   is delegating to cslol-manager.exe the intended approach for third-party launchers?