There is no universal production turnaround. A simple controlled video may move through the process quickly; several sites, contributors, edits and approval stages can extend it substantially.
B-roll is purposeful supporting footage that shows what a speaker or main sequence describes, provides context and gives the editor truthful visual options.
Repurposing is not uploading the same file four times. Keep the central idea, then rebuild the opening, framing, context and action for each viewing environment.
Short-form and long-form video do different jobs. Choose by the viewer’s question, the evidence needed to answer it and what should happen after viewing.