Other than the article LD published on making this work, I doubt you will find anything else more formal. You could ask your LD account manager to issue some sort of statement I guess, but that probably would be backed up by you taking services from them to actually implement it.
As an FYI when a salesman asks me 'Does LD integrate with xyztest' - my usual curt and unhelpful answer to them is 'what do you mean by integrate'. Clearly I wouldn't be curt and unhelpful here :-), so if the work LD have published gives you the level of integration you are after, and if you pay the LD Systems Integration team (or an LD partner like us or someone like us) then it will be supported.