If you look back to page 19 of this thread, you'll find that Pegasus77 posted a detailed description of the 340-300 autospoiler logic parameters in response to my earlier question.
Indeed.
But - unless I missed something - there is no mention of
manual override should it be called by the crew.
I'm probably completely ignorant but some sort of "max deceleration panic button" (automatically providing the most aggressive settings of anti skid, spoiler and reverser, at the possible expense of their durability) would seem to be a useful option in cases such as this.