Is a convert allowed to conceal the fact that they are a convert, as long as they don't outright lie or take a position of authority that a convert is not allowed to take?
Excellent question. If you haven’t noticed from my previous answers I’m an expert in the subject, living in Guatemala by default I have dealt with many conversions. You have no obligation to reveal you are a convert nor is it anyone’s business. Unless: you are joining a new community and you need to provide proof you are Jewish or are in Shidduchim. If you’re conversion is merely lechumra you don’t have to mention it until you have met a potential match a couple times (a descendant of anusim is considered a full conversion now a days). The Rov of Crown Heights, HaGaon HaRav Zalman Shimon Dworkin z”l once officiated a wedding of a convert lechumra and a Cohen being that as the term implies, when there is a Chazaka(1) that the person is Jewish he/she only goes through the process of conversion out of doubt. Even if you are a full convert there’s no obligation for you to explicitly express you are a convert in a resume, that’s up to the other side to find out when making reference calls. Nevertheless, most of the times in Shidduchim it’s better to be upfront about things. When it comes to getting called up to the Torah I asked a Shailoh to a prominent Rov who said that although lechatchila it’s better to use ben Avrohom Avinu, in a case where the person is sensitive you may omit Avinu or even say ben Reb Avrohom. A convert who’s biological or adoptive father is Jewish or another convert in a case of embarrassment or feeling uncomfortable because of Kavod Habrios he may be called up by the name of the person who raised him. It is evident from various Gemaros that you are allowed to lie in cases of embarrassment whether you are the subject or someone else. In truth there is nothing to be ashamed of in this case but you don’t have to carry the title as a badge. The same Din applies regarding a Baal Teshuva. If a random person asks you if you are a Ger directly and you’re not comfortable with answering, I suggest you somehow cleverly dismiss or ignore the question and change the subject making it clear you don’t want to touch it. Hope this answered you’re question!
- The Din might be different when the Giur Lechumra is done because there is an essential Sofek without a Chazaka like in a case of IVF where the egg belonged to a gentile Jewish woman. In such a case I don’t know if the Giores Lechumra may marry a Cohen. See this Teshuva.
A convert is inevitably forced to reveal his past in certain cases. One such case would be a marriage, in which not only is it standard practice for the officiating beis din to require proof of one's Jewish identity, but also where his name will be recorded on the kesubah as "ben Avrohom Avinu". Similarly, when called up to the Torah a convert will be revealed for the same reason.
Nevertheless, a convert doesn't have to reveal his status to everyone. Additionally, there is a mitzvah to not embarrass others (based loosely on Vayikra 19:18, 25:17), so if a convert would become embarrassed if his past were revealed, it seems to me that one should not spread the information when not absolutely necessary.