TL;DR: there are two new settings to hide/warn about certain content, instructional text has been added to the route map screen, SG's OST is available as free DLC, Tix's route is still a work in progress.

New settings

This update introduces two new settings aimed at people who want to play Sable's Grimoire, but don't want to view sensitive content. The first time you play Sable's Grimoire, you will now be presented with a content warning screen which prompts you to set the new preferences. Initially, "Mature Content" is enabled, and "Bad Ending Hints" are disabled, so the default experience remains the same as ever.
What can be classified as "mature content" is obviously subjective, and I don't intend to go on a crusade to make this a G-rated game. Instead, I've taken a conservative approach to this setting's implementation and only hidden the most extreme content. The biggest change is that choosing to disable this content will stop you from going down Jorou's route. Jorou's route contains many mature themes and several dark, confronting scenes, which cannot be removed without turning Jorou's route into a fractured mess. As such, it's all or nothing with her route. Other than that, there are only two scenes affected by this setting. One is a bad end, the other is the violent conclusion to a side-story. So even if you opt out of viewing mature content, the majority of Sable's Grimoire will remain completely unaffected.
Even if you're okay with mature content, that doesn't mean you aren't frustrated by those pesky bad ends. By enabling "Bad Ending Hints", you will be shown a small knife icon on the far right side of choices which lead to bad endings. You won't be blocked from reaching bad endings. This just provides a subtle hint, so if you're wary about reaching bad endings, you may exercise appropriate caution.

Route map instructional text

This is a minor addition, but I think some players might find it helpful. The route map isn't just a tool for viewing which route you're on. It's also an interactive checkpoint system which you can use to restart from a later point in the game.
A small piece of instructional text has now been added to the route map to make this feature easier to discover.

OST

https://store.steampowered.com/app/941900 As was recently the case with Tomboys Need Love Too, I discussed with the composer of Sable's Grimoire, Mario Luengo, the possibility of providing the original, high quality WAV audio files of SG's soundtrack as free DLC. The OST is not downloaded by default (it's bigger than the game!), but if you choose to download it, a new option of "Soundtrack" will come up when you attempt to launch Sable's Grimoire. Selecting that will open your operating system's file browser (should work on Windows, Mac & Linux) in the directory containing the music files.

What's next?

I'm still working on Tix's route for the time being. I don't have an ETA yet, but it's looking like December at the earliest, more likely early 2019. Additions after Tix's route remain undecided. There will be more new content after her route is complete, but the nature and timeline of that new content is yet to be confirmed.