[Simple]

Usually firmware updates are delivered by PSA in "C:\AWRoot\dtrd\firmware\appli.com". I have 4.3.4, but that's because I keep whatever possible as is when I compile my updates.
Also, you will find few APPLI.COM files here "C:\APPLIC\LEXIA\MajAppCom\APPLI software\xxxxx.com".

I noticed that Maitresox has disabled the Firmware Auto Update when you start DiagBox after connecting and recognizing the device. Probably to avoid failures or blocking!! In any case, if you are using one version, it isn't really needed. Because you will use the checker to know which version do you have, and you may use the checker to update to what ever version you want...

See Post #1
I have packaged DiagBox v8 Engines to replace v7, this way nearly everything has been updated to Diagbox 8 (the old engines running Java 6 and the new are on Java 7)...

Once again, This is for personal testing or experimental purposes, and I hold no responsibility for any illegal or improper usage. Use at your own risk, you are responsible for any damage that may occur to your system...