If or when the dev adds the FMC POV, there are many ways to implement it from the many examples here on F95:
1. At the start of the game, the player chooses either the "MC Only POV" or the "FMC Only POV." No switching between POVs after that.
(Examples: Turning the Page, On the Edge)
2. Similar to No 1, but it's "MC Only POV" or the "All POV." In the "All POV" option, the POVs change as the story unfolds, with no input from the player when the POVs change.
(Example: Falling Undercover - Nox Syndicate, A Promise Best Left Unkept)
3. Game only has the "MC Only POV." The scenes involving the POVs of the FMC and of other characters are in a "Recollection Room" that is accessed separately. (In RenPy, this would be like having a subpage in the Main Menu where the sexy scenes not seen by the MC are unlocked as the player progresses thru the game.)
(Example: Whispers of the Dark Elf and almost every single RPG Maker game.)
4. Game starts with and mainly sticks to the "MC Only POV," but at certain times, the game gives the player the choice to jump back in time to certain scenes but this time from the FMC's POV.
(Example: Sunken Promise, Cursed Forest Quest)
5. Game starts with and main sticks to the "MC Only POV," but at certain times, the game gives the player the choice to "Stay with MC POV" or "Go to FMC POV" when the in-game characters are not together but are doing different things at the same time period. If the player decides to go with the FMC, the at the end of the scene, the player goes "Back to MC POV." Here, there is no backtracking, so the player has to use saves to see the other POVs that were happening at the same time.
(Example: Locked in Chastity)
Still though, the really big issue aside from the POV thing is if the game will have choices. Having those will really lengthen the development time because writing and making CGs for all scenarios will take super long.
The good thing about the dev is at least there is an outline of the story to prevent writer's block. Hopefully, the dev has already outlined the entire game, so the dev already knows how the story will end and the penultimat scenes leading to the end.