Questions are fine.
You are learning more about your situation and how to address it.
Yes, tight/fatigued piriformis and glutes can be an impacting factor to sore back and hamstrings
Here are a couple episodes to check out.
Episode 234: Improve Your Proximal Hip Mobility and Nerve Tunnels
Pro Episode # 45 – Pro user Request Friday: The Dread Piriformis Syndrome (Like the Dread Pirate Roberts…but Different)
Less concerned about when more important that you are addressing your tissue.
Pick one thing to focus on during a session.
One idea, one problem, one area, one position.
You will do more tomorrow.
Soft tissue work is done after training or before bed.
Joint capsule/band work is ok before training.