This is my current EXE.xml patterned closely after yours except for the section to start FSUIPC7 instead of SPAD. FSUIPC autostarts as expected but the AFC_Bridge application does not.
<?xml version="1.0" encoding="Windows-1252"?>
<SimBase.Document Type="SimConnect" version="1,0">
<Descr>Auto launch external applications on MSFS start</Descr>
<Filename>exe.xml</Filename>
<Disabled>False</Disabled>
<Launch.ManualLoad>False</Launch.ManualLoad>
<Launch.Addon>
<Name>AFCBridge</Name>
<Disabled>False</Disabled>
<Path>C:\Users\harve\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCach
e\Packages\Community\AFC_Bridge\bin\AFC_Bridge.exe
</Launch.Addon>
<Launch.Addon>FalseFalseFSUIPC7C:\FSUIPC7\FSUIPC7.exe-autoFalse</Launch.Addon>
</SimBase.Document>
This is very strange because a shortcut with the identical path to the AFC_Bridge application reliably starts it manually.