I'll give a try
From my experience, most of people with LBP and significant stenosis/LE symptoms are relieved with sitting and aggravated with standing/walking. I've also noticed a lack of hip extension ROM/tight rectus and thoracic extension hypomobility. So, a lot of what I typically do is rectus/hip extension stretches/ROM exercises (while avoiding lordosis/lumbar extension) and thoracic mobilization manual treatments to improve extension ROM and flexibility as appropriate. Lots more treatment/rationale than above, but for me is dependent on each patient and tailored as such.
Whitman et al 2006 had positive outcomes with a flexion based routine plus a walking program, but better outcomes with manual treatment to the hip/lumbopelvic/thoracic spine in addition to above.
Protocol: improve hip extension/thoracic extension ROM while avoiding lumbar extension, improve lumbar flexion/posterior pelvic tilt strength/mobility, institute a walking program.