Upvote:4
As you said yourself: very small numbers converted to Judaism. It is not a missionary religion. Even under the best of circumstances, there aren't too many converts. In the occupied countries those numbers wouldn't be much different. As far as I know converts were send to the camps as well.
I'm Dutch. Quite a few Jews were hidden by the Dutch (most notably: the Frank family). Those Dutch who hid Jews were not Jewish. Usually Protestant (Calvinist) or Roman Catholic. When discovered, those Dutch families could consider themselves very lucky if they were sent to prison. Most often they were sent to concentration camps as well. That's what the Germans did with non-Jewish people who hid Jews. I can't imagine them treating converts any better.
Upvote:7
In theory, people that were converts to Judaism and were not "racially" Jewish had some protections. In practice, SS "death squads" often failed to observe such niceties, and swept up many in their anti-Jewish actions. Basically, if someone is engaged in "mass killings," they might not look too hard for "exceptions."
Even without the above, the converts were in a very precarious "mixed" position. A clue to this may be gathered from the fate of "Mischlings", or "mixed bloods" of the first degree. These people were considered "partially" Jewish in having two Jewish grandparents, but not three or four. Their problem was that they would be considered "full" Jews if they married full Jews, or observed the Jewish faith.
The "converts" were also "mixed," in the sense of being philosophically, though not racially Jewish. They could also diminish their status by marrying full Jews. And it would have been wise for them to downplay their "Jewishness," that is to hold Jewish beliefs, but not to be "active" in the Jewish community. The "Karaites" of Russian Crimea managed to walk this tightrope--up to a point.