That crest might make it so that a character whose preference is to refuse things like condom-less sex will allow it instead.
There is no clear indication on that one, unlike the ones like breedgasm, which does exactly as it says. With that one, it specifically says she gets psuedo-pregnant when you climax inside and that is what happens, although not as visible as one would think, it barely expands the girl's stomach region to indicate this status. Unfortunately, I did try that on this girl. I specifically chose one I set all permissions during sex to no on and she still forces a condom on me and forces me not to get too rough with caressing with the command crest applied. It also specifically mentions talking in the description, which tells me it is supposed to do something when in conversation. I would go to Marco's Patreon since it is a Marco mod according to his Patreon, but he specifically has comments set to patron only.
EDIT: Got clarification from the Discord, it is basically a 'can't say no' crest. Whether you ask to date her, ask her to lunch, or ask for sex, even on your first interaction, she will accept. This also provides a not so common opportunity to see her speak the line she gives when not a lover and asking for sex and she says yes. Most normal cases end up with a girlfriend request from the girl or the player before sex ever even comes up, though that can be somewhat avoided with certain trait and personality setups.