I don't love your use of the word "should" tbh. Telling people what they should be comfortable rarely works well.
I personally don't have a problem with TM in my women spaces. They are women, however they identify, and as such, they have the same threat profile as women.
There are a couple of wrinkles which may mean that isn't a good solution though.
TM often pass much more convincingly than TW, so if you insist on them sharing women's facilities, you create a situation where women cannot easily police who is in their single sex space.
Where TM pass convincingly, you create a situation where women who are are uncomfortable with men in such a space may feel threatened because it will not be clear these people are actually women
TM may not want to use the women's space as they ID as men
Offering single sex facilities and mixed sex facilities is the best answer for anyone who just wants to pee. Those with different agendas, for example, those seeking affirmation through access to a space aligned with their identity, should be managed kindly but with a firm no and pointed to the mixed sex space.