Why does qBittorent Portable not use qBittorent's portable version?

As qBittorrentPortable.ini shows, qBittorent Portable is all over the registry and app data folders, not to mention a whole custom code in custom.nsh.
That's a lot of writes which are not needed since qBittorent has an official portable mode which can also be achieved with a command line parameter and/or an environmental variable (see both here). It's also mentioned here.
So there are 3 ways to activate portable mode, why not using any of them?

This might also apply to qBittorrent Enhanced Portable, and might solve issues like this and that.