Top 3 to final (Q) + next 3 fastest (q)
Here are all the guys with PBs under 3:34 in each heat (bold and front of list if under 3:32)
Heat 1 - (Koech, Kessler) Cook, Engels, Alvarado, Teffra, Strand
Heat 2 - (Hocker) Green, Prakel, Allen, Wynne, Reniewicki, Waskom
Heat 3 - (Nuguse, Ciattei) Martin, Murphy, Houser, Fernandez, Suliman
Assuming at a minimum the 5 bolded are safe, that leaves 16 guys between 3:32-3:34 for the remaining 7 spots. Some of those like Strand and Green will get through barring disaster, but it's going to be a bloodbath for those remaining spots.
Who you got?
I'll say Koech, Kessler, Strand, Alvarado from H1, Hocker, Green, Prakel from H2, and Nuguse, Ciattei, Martin, Murphy, Houser from H3