Production - Workstation Working Hours not validated by Production Planning Tool

Using the production planner appears to follow the ‘Planned Start Time’ entry instead of validating working hours against all workstations in BOM. I’ve confirmed that the Manufacturing overtime flag is NOT set. Is this by design or is something broken here? I’ve confirmed this by setting three separate workstations with different start times (none of which are earlier than 8am) and set a ‘Planned Start Time’ for 4am.

If by design, what are the benefits to setting working hours for workstations if they aren’t validated against Production Orders?

ERPNext 10.1.75
Foundation 0.0.1
Frappe 10.1.67
Installed with ‘–production’ flag