I don't know about other Lubavichers, but Dan and jj post OU-D sales all the time, and IINM, Chabad considers it at least a חשש איסור.
funny story....I was asked to review the Kashrus at a college cafeteria.
I immediately noticed that there was no system for produce checking or general control.
Further inspection revealed
Bishul akum and gevinas akum
When questioned the one in charge said to me
" Mayshe, it's stam kasher. It's not cholov Yisrael, pas yisrael, bishul yisrael, gevinas yisrael, (bas yisrael- ok, I added that one) It's stam kasher."