Final diligence on a $4M seed, written to an honest recommendation

I'm a partner at an early-stage venture firm — seed and Series A, $180M fund three. We're in final diligence on a seed deal and I want a full institutional-grade workup. The company is Meridian Grid (fictional for this exercise, but treat the work as real): they retrofit commercial rooftop HVAC units with a $900 sensor-and-controls kit that cuts energy use 22 to 30 percent, sold as $149 per unit per month SaaS. Founding team is two ex-Carrier controls engineers and a former Stripe enterprise AE. They have 41 buildings live, $38K MRR growing 19 percent month over month, and they're raising $4M on a $24M post.

What I need before Monday's IC: the market truth — how big is this really, who else is attacking it and why incumbents haven't; the unit economics teardown at their pricing with realistic CAC for mid-market building owners; the diligence question list I should put to the founders, ranked by what could kill the deal; the risk map with pre-mortem; and it all lands in an IC memo with your honest recommendation — invest, pass, or invest-with-conditions — and the terms I should push on. I want the memo to look like it came from a top-decile firm, because it's going in front of my partners.