As the company does not like us stalling the aircraft, I can only comment on what the simulator does.
As the speed decreases into VLS, the speed brakes, if deployed, auto retract, and prior to Alpha Stall Warning, the auto trim stops. To continue speed decay, you need to hold pressure on the side stick to prevent the nose dropping. If the stick is released, the nose drops and speed increases.
To check and make sure the THS was not at the stop, I put the SIM into direct law, and trimed up. Was able to trim an extra 4+ units to what was shown on the flight control SD page for Stall. This was in the 380 sim. Tried the 330 SIM next door, same result. There is no trim wheel in the 380, only two rocker type switches.