I have unofficial information(study guides, etc) for the 747 that say that it is inhibited once below 5' for 2 seconds until 3 seconds after climbing above 5 feet.
Then on the 777 I have similar but it says inhibited below 2 feet until 3 seconds after climbing through 5 feet.
But in both cases, none of this is in the official manuals. The FCOM in both just says "The TO/GA switches are inhibited when on the ground and enabled again when in the air for a go–around or touch and go"