The sentence below seems to me to be correct:
They have the technology that is documented the best.
But, can I use a little bit changed sentence as follow:
They have the technology that is the best documented.
The sentence below seems to me to be correct:
They have the technology that is documented the best.
But, can I use a little bit changed sentence as follow:
They have the technology that is the best documented.
Both of the sentences make perfect sense grammatically, but I think the clearest way to write it would be "They have the best documented technology", as it's more streamlined and less awkwardly worded than the other sentences.