I purchased a Bravia KD55-AF8 OLED TV because of the picture quality and sound output.  I did not have space for a soundbar but did have a desire for improved low frequency sound.  I discovered the AF8 could reconfigure the headphone output to be a dedicated subwoofer output.  So I matched the TV with a REL T5i sub bass system [subwoofer].  It works wonderfully and I am happy with this.  The TV is controlled with an Android operating system.  I am not a fan of the clunky interface, slow response and the fact it has often crashed when pushed to the limit.  It is Android version 7.0.  I took a look at the Bravia AF9, the alleged replacement to the AF8 and it had Android version 8.0, which has a different interface and is customisable.  I further understand that Android version 8.0 will be available as an update to my own AF8 later this month [January 2019].  Firstly, is this the case, will Android version 8.0 be available for the AF8?  And if it isn't will the AF8 get an update to Android version 7.xx?  Secondly, on inspection of the sound settings on an AF9 using Android version 8.0 there is no facility to convert the headphone output to become a dedicated subwoofer output.  Is this because the AF9 is not 'hardwired' for this or has Android version 8.0 dropped this facility?  Thanks for taking the time to read my question.  Vince