Currently Custom platform doesn't support the ability to program the following steps when retrieving a password/session:
pre (before retrieval)
interactive (while having a session)
post steps (after the session is terminated or the request has being expired)
Also there is no variable to forward the current user that has requested the managed account and forward this to the managed system.
This would open the possibility to harden the system even more (including just-in-time and just-enough privileges) and include notifications/audit events with the originating user.