Greetings Huib,
ww2aircraft.net/forum/threads/dornier-do335.42696/
I am sorry I cannot add any thing about "Hauptmann Miersch"'s name. However, it seems he was not only an expert about the Ar 234 but the Do 335 as well. From the source above, he apparently made a faultless belly landing in Do 335 AM225 at Merville, France, on 13 December 1945.
Best regards,
Jim Geens