Using Journeys with Core HR slave?

Summary:

We would like to understand if it is possible to use journeys when Core HR is slave.

Content (required):

We are using Core Hr as slave and all information concearning employees are transferred to the system using HDL, new hires, transfers, contracy changes and so on. In this case, considering that every action in Core HR is performed using HDL, would it be possible for us to use the journeys? Will they be triggered with the actions even if it is performed with HDL?

(We are considering also to use expressione language for eligibility profile, if someone has already tried, can please share your imput?)