Seiki 65" Smart TV Disable OS?

I bought this TV from Target on this deal:

It's OK, but I have a chromecast with Google TV hooked to it and whenever it comes from standby, the bloody smart TV OS is showing until I pick up the native remote and press exit.

Real pain if I'm already seated with KFC all over my lap and remote is somewhere else.

I've been in contact with Ayonz who handle customer service for the brand, and they said to try a menu option for OSD time to set to off but there is only 15,10,5 & Always. Also I think this relates to OSD settings menu rather than smart OS menu.

I think I'm looking for a service menu which most TVs have like soniq, etc where you can change more advanced settings.

Googling I found MENU+000000 or something but doesn't work on this model so far. Soniq uses the same kind of thing but might be MENU+897564 (for example).

Does anyone have any clue please? Cheers.