hey all! im a cis woman with a gender-fluid/questioning AMAB partner of 5 years. they have been exploring their gender for 2 years now, usually starting to present a bit more GNC in social activities and such which has now become into more often than before (which i adore! this is really no issue for me since i always did identify as a lesbian).

They have seriously started to consider transitioning to female, which i wholly support and will be there for them whatever happens, however i kind of feel they have to do a bit more digging beforehand since they are currently mentally "all over the place". I don't want to sound unsupportive or anything, i wouldn't like for them to feel unvalidated or to minimize their experience, but i do believe there is a great deal of work that goes into deciding to medically transition and start HRT and don't feel they are ready to take that leap. They seem to romanticize the idea of HRT and envys a lot of MTF people online since they "get to be so attractive".
They have struggled a lot with body dysmorphia (not dysphoria, they don't feel any dysphoria particulary, which is why they hadn't considered transitioning seriously, They are genuinely fine being a male which is why they often consider themselves more as gender-fluid than outright transfem) since they have always been overweight and struggle with food issues. They also have a history of struggling to fit in in the past and feeling as if they "failed" as an AMAB since they never were good at flirting/seen as attractive and stuff along these lines. In general this is a huge problem they have struggled with: feeling as if they "missed out" in their youth and wants to make up for the "lost time" of not being able to flirt, have tons of sex, feel desired (especally this) etc etc. We are very happy and fulfilled sexually and he is aware that this fear of his is, well, a fear more than a real desire to be a female.

Os there any sort of support of tips i can give them to help them on their journey? Is there any way to be able to "differenciate" when transitioning medically is a good idea? In general I need help with how to navigate this situation and how to be supportive while also being critical in the "why" of their decision?