I did it: I fired up up the seedling bank, lights, heat mat, timer, fan, mouse traps, and all! And everything still works.
I discovered this nifty When To Start What “calculator” from Johnny’s Seeds. I’m behind, of course: should have started three weeks ago. It doesn’t matter for lettuce and kale and the like, because those I sow in succession anyway, so I just missed the first batch. It does matter for leeks and onions, which need  the entire season to mature (ca. 110 days). Also late, but to a lesser extent, with the celery and parsley.
- Onions: Crystal Wax Mini, Red Marble, NY Early , Rossa di Milano
- Leek: Lincoln, King Sieg, King Richard
- Celery: Safir, Tango
That filled up the heat mat real quick! Unheated are:
- Chard: Fordhook Giant, Bright Lights
- Lettuce: Black-Seeded Simpson, Tango, Rouge d’Hiver
- Mache: Verte de Cambrai, Erba Stella
- Claytonia
- Kale: Winterbor
- Spinach: Space
I used only coir (coconut fiber). Let’s see how that goes.
I gather you have learned, as I did, how essential mouse traps are to indoor seed starting. Two or three years ago, the local mice decided my seed-starting table was a salad bar and ate EVERYTHING. I was not best pleased….