Had a case with legal advice. ÖRAG readily arranged the lawyer and apparently also paid. If the case is resolved with the consultation, you do not have to pay any deductible. This was the case for me.
The problem with construction is: usually in these times you want to have the construction finished more urgently than the contractor. That means realistically, arguing for months, possibly even years until you might get your right is not as high a priority as simply being able to move in finally. In this respect, the BH-RSV is not that helpful for you either. Of course, in all the preliminary stages it is good to have legal support in order to even find out where you stand. Even in correspondence, a letter from a lawyer can sometimes achieve more than self-written defect reports, even if formally correct (although depending on the character on the other side, this can also backfire). Therefore, there are still many arguments in favor, especially for uncertain people.
I see the greatest advantage after the construction phase, with possible warranty claims, because then the contractor usually has no interest in fulfilling his duty and then you have a corresponding lever that you can use freely. Is it worth the premiums? I will be able to say that in 5 years...