Nice work, Smangs.
Opa would be happy to see his grandson interested in his military career.
I did not see the remark about the scar on the discharge papers you showed, but his pictures as a Führeranwerter and Standarten Oberjunker definitely paced him with us "bad guys"
Indeed in two years (from surrender until discharge) a scar would be just a scar. My remark about it pertained to , that allied troops were very keen on finding "bad guys"(sic) amongst the good guys. And a fresh wound or fresh scar in the known place of a Blutgruppe tattoo could have sent red flags to the interogator. As far as that goes he sure was lucky.
Keep up your research, and be proud of your Opa. People of the present time may not be able to understand motivations and circumstances. But the more you dig up, the more you will understand.
Keep us posted on you uncle also !