Ouch

• warm up with Stamp; keep tongue in a light whistling position
• relaxed inhalation; let lips relax outward
• wrap lower lip around teeth when reforming embouchure
• massage both upper and lower lip when feeling pain or tone getting constricted
• engage scapula when ascending; pull them down and back

The scap thing didn't work. Tone was thin. Pulling the muscles back created tension.

I'm going to try fish face exercises to strengthen the lower lip. Sort of like the PETE but without the device, with an open jaw and lips just extending the lower lip outward until I get a burn. I am also considering trying long phrases with corners engaged, as described in this youtube: