As I was typing another reply , my whole PC fainted! I'm not going to risk a repeat ...
This year I hope to reduce my queasiness and waste with Lobelia by taking someone's advice about sowing them into a "20-row" tray. That's a 1020 tray (11" x 22") with 20, 10-inch-long rows.
You can dump the whole row out and then GENTLY TEASE it apart with as many seedlings as you want in each chunk. (None of this wanton hacking and slashing with axes and chainsaws SOME people practice! )
Last year I tired to sow 10-15 seeds per cell (72 cells per tray, in 12 6-packs). It seems I got more like 30 seeds and 200% of them germinated. Needless to say, I was too sissy to tear those delicate little vermicelli apart ... you say they're indestructible? I just START to tug at their little toes and I can hear them scream.
"Owww! Ouchie! Le'me go, ya big bully! I don't go pulling on YOUR hair!!!"