I wish there was a middle ground between the base game and skipping Fabien's bits entirely.
I'm currently on my third playthrough of VTMB2 and for the first time I selected the option to skip Fabien's segments. They were simply too long and dragged down the pacing of the game. That said, they also contain most of the important story beats and losing them entirely just feels like gutting the game's narrative. It doesn't even keep the parts where the Gardener speaks to you in the field of flowers, which feels really strange because those aren't even really Fabien segments. He's talking to Phyre. I really wish there was an option to keep the important bits while trimming the fat, so to speak, so I'm going to attempt to brainstorm how to do just that.
The Cigarette Girl: Skip the opening at the police station and just start outside the Makom Bar.
Blood Sisters - The Night Out: Skip the entire investigation around the city. Just use Fabien's Scry the Soul ability to discover that Verona has a twin sister she's hiding. Then teleport Fabien to outside Atrium.
In Memorium: Teleport from Weaver Tower directly to the Pioneer Square crime scene. Use Spirit's Touch on the elixir to discover it's memory enhancing properties without running around to Safia and Mrs. Thorne. Move Tolly to the scene so we can question him right there about who would need the elixir. Teleport us to right outside Willem's Haven.
The Mother: After investigating the crime scene, teleport Fabien to the police station. After looking through the files, Fabien realizes he knows all these people. Instead of hunting them down around the city, have Fabien go to Benny's office and request that they be brought in for questioning. Fabien can then question Mr. Lemon, Guru, and Carla in the holding cells downstairs. Teleport Fabien to St. Stephen's.
The Prince of Seattle: Simply remove Tolly and let Fabien enter the elevator. This is probably the most egregious example of meaningless time wasting in Fabien's part of the game.
Service, Pride, and Dedication: Skip stealing the tape recorder, speaking to Ryong, snooping in Cambell's office, talking to Tolly and Benny. Begin with Katsumi telling Fabien where Cambell is.
I think these changes would preserve the core narrative beats in Fabien's segments while trimming the majority of the walking-simulator portions and meaningless busy work that drag down the game's pacing.