I’ve seen many do not visit Beis HaChaim (cemetery) during Yud Beis Chdesh (the first twelve month) do so. It’s also mentioned in the Nitei Gavriel. Is this more of a Kabbalistic thing or something that Brisk/Rambam follow (they don’t go to Beis HaChaim anyway) or is there a more "mainstream" view that says one should not visit any Beis HaChaim during Yud Beis Chodesh? Of course, there are those who do. I’m not suggesting that those who do, are doing anything wrong, of course ...
Shalom, In the work "Mourning in Halacha" by Rabbi Goldberg (Chapter 42:2) he writes: "One should not visit the grave during the first year to pray for a sick person's recovery, or for other matters, because during this time the deceased is still going through his time of judgement. Instead, one should pray only for the elevation of the departed soul [Zichron Eliyahu, citing the Zohar (Parshat Vayechi). But Darkei Chaim VeShalom states that if the deceased was a great man, one is permitted [to pray for a sick person or other matters even during the first year].] Many have the custom to minimize visiting the grave during the first year, even to pray for the deceased [Zichron Eliyahu. The same ruling is given by responsa Melamed LeHo'il (Yoreh De'ah 144)]. If one goes on a distant journey, and it will be impossible for him to visit his parent's graves later, one may visit them even during the first year [Responsa Melamed Le'Ho'il 144]." Blessings.