In our system, gay identities - e.g. veldians, lesbians, and cenelians - are the majority and could be seen as the "default".
There are a few explanations for this, but we're probably just wired in a way where we want to associate, including romantically, with categories of people we consider ourselves or want to be. For someone who is used to being thought of as a woman, that often manifests as being a lesbian, and for someone who considers themself or wants to be a man, that often manifests as being a veldian.
Most headmates in our system are attracted to the same genders or gender categories as themselves and are not attracted to people who do not have genders or gender categories in common with them. This is the most common blanket definition of "gay" in our system.
This would mean that a genderqueer man who is attracted to men and genderqueer people (other than those whose genderqueer identities are of different alignments to the first individual) is considered "gay" without having to specify "mspec gay", at least in our way of viewing it.
However, not all headmates in the system who identify as gay are attracted to all the same genders as themselves. For example, some members of the system are genderqueer veldian men who are attracted to men and masculine-aligned people, but do not seem to have any strong attraction to genderqueer people who aren't also man-aligned or masculine.
While we know this experience and perception isn't universal, we feel that different types of gay relationships feel different. For example, some of our genderqueer men attracted to men and genderqueer people feel that their relationships with genderqueer people feel or are different from their relationships with men. Explaining the particulars of why, however, would require us to have more experience than we do or are likely to ever have, so it's not something we're able to explain, other than that our gay men usually don't feel represented by lesbians and vice versa.
This is part of why using specific terms for "gay" is relevant to us. Concepts and depictions of lesbian relationships do not feel like they represent the veldian relationships in this system, and vice versa. Some headmates also behave differently in relationships that are MLM versus relationships that are NLN, and they want language to express that.
While we don't have enough experience to be sure, we think the collective preference for a romantic partner would be that they share as many gender alignments with us in common as possible. While, due to identifying with a wide variety of labels, this isn't realistic to expect, someone who broadly identified as a genderqueer man is someone we would consider to fit our two primary collective gender alignments.
However, it is much more common for people to be binary men than for them to be genderqueer men. As a result, a lot of our attraction is expressed towards people or characters who are or are usually interpreted as binary men. However, in our self-ships, most of our canonically male F/Os are genderqueer in some way, or don't consider "male" the only gender they're aligned to. This is closer to our preference than their canonical or assumed gender.