Workspace heap retention versus OS release in Dyalog APL memory management

Goal: ascertain if Dyalog APL releases memory obtained from erased arrays back to the operating system while the session remains active, given that ⎕WA may show recovery while OS process size stays elevated.

Uncertainty: documentation notes that the interpreter may retain freed space in its internal heap for reuse, but does not specify when or if that heap is returned to the OS, and observed differences across versions and platforms leave the behavior unresolved.

Does Dyalog APL return freed heap memory to the operating system during a live session?

Under which version, platform, or MAXWS configuration does such return occur, if at all?

Is there a documented mechanism or configuration option to control or trigger mid-session heap release to the OS?