Thanks for the update. I was just searching for an answer to this very question.
On my version however Function 2 does nothing. I wonder if this is a software version related thing...
I'm interested to understand, if you disable amp modelling, does this also include speaker modelling? What's the overall effect on the sound? Do the gain/eq controls still work? Is the amp now a "pure" non-modelling amp at this point?
Cheers
Neil