I feel like you're describing the most radical of the radfems. They definitely do exist, but they're the extreme of the group.

Most radfems I see (at least online) accept straight women but warn them to not override radfem beliefs in their space with "not my Nigel" type of behavior. As in, "read the room and stay on-topic". And they accept FTMs/TIFs, they believe they're women who are indoctrinated by patriarchy and such and just need to find their way back to a female community to accept themselves.

I haven't seen a whole lot of division by sexuality other than lesbians sometimes feeling like they're not heard in radfem spaces, but that's because lesbians in general are being shit on everywhere except for porn. They thought they would find community in radfems because "woman-centered", not realizing there's a whole belief system that goes along with it that they may not subscribe to.