he alrdy got into trouble for being suspected of using his nobility name before, I don't think he would want to make it an actual case
You seem to have misunderstood my comment. What I’m saying is he could have asked Snow and/or her family who are nobility as Elma the adventurer, this action has no relation to his former status. I emphasize this fact that he is not using his former affiliation with the phrase “his original house aside”.
In short: at no point in any portion of my comment that you quoted that I even mentioned or suggested Elma using his former family name. If anything, it’s the opposite.