Where am I losing speed / efficiency?

For context, Ive been floating around a 4-6 hdcp. Driving is actually a strength for me, I'm very good at keeping it in play and hitting fairways. But I'm motivated to try to add some distance this off season. This was my highest ball speed of this session @153 MPH and ~250 carry. My launch monitor doesn't measure club head speed.

I'm seeing that I look flat, head moving back, and spinning out on my left heel... Not sure which or if any of these are opportunities for adding speed..

Anyone with more of a knowledgeable perspective care to weigh in on what to work on for swing speed?