Its a completely new FCU but closer to the 365 than the 320 it looks like
According to AI both of the inferior P320 kluges hacked from the hammer fired P250, the partially captured torsion sprung lever striker safety, and the when so equipped manual safety that did not block the sear directly, both have been redesigned similar to the P365, so that's great news!
Manual Safety
Trigger Bar Block: When you flip the safety lever up into the "safe" position, an internal post or shelf mechanically locks into a recess on the trigger bar. This physically prevents the trigger bar from moving forward or rearward when the trigger is pressed.
Sear Block: Simultaneously, the safety mechanism places a physical barrier or hook directly underneath the sear assembly. This ensures that even if an extreme external impact or component failure were to occur, the sear is mechanically blocked from dropping down to release the striker.
Striker Block
The SIG Sauer P385 utilizes a fully captured coil spring and plunger striker safety design, similar to the architecture found in the P365 platform (and most others since forever).
The Shift in Safety Architecture
The P385 represents an entirely new "ground-up" design that deliberately moves away from the inferior internal safety mechanics of the older P320, which were derived from the hammer fired P250.
The P385 adopts P365 Logic
For the P385, SIG Sauer opted for a clean-slate, modernized design. It utilizes a traditional vertical plunger driven by its own captured vertical coil spring located directly inside the slide. This plunger physically blocks the striker's forward path and is only lifted out of the way vertically when the trigger bar rises during a complete, deliberate trigger press.