Hi... to find switches you must do this:
Run offline installer in Virtual Machine and wait to the program is iddle (yo can see Google offfer window)
Go to %temp% folder and copy _av_iup.tm~a*** folder to other location
Finalize installation and then open C:\ProgramData\AVAST Software\Persistent Data\Avast\Logs\Setup.log file with Notepad
Search for instup.exe" /edition (in line 9 +-)
Command: '"C:\Users\Administrador\AppData\Local\Temp\_av_iup.tm~a00668\instup.exe" /edition:1 /ga_clientid:124e581d-f162-47a7-a518-f372afb62e8d /guid:21e128e4-bea6-4bc6-b618-a46c75ccefec /prod:ais /sfx /sfxstorage:C:\Users\Administrador\AppData\Local\Temp\_av_iup.tm~a00668'
You can edit comand like this:
You must run command from the folder that contain Avast files copied from temp folder
Change C:\AvastFiles for your own folder
edition:1 is Free version, you can discover the other version numbers by runing same steps installing other Avast versions
Cheers... ;-)