Please let me know if I'm being dumb, but I currently need to 'research'/build a Electro-Magnetism lab. One of the effects of that is that I can build Lab Construction Cores, but I need two of those in the first place to 'research'/build the initial lab. It seems impossible to me.

I've just had the same issue.

More specifically the labs themselves start unlocked (as well as lab mechanisms) even though the previous tech, wood processing, says it unlocks labs. Seems like the by default unlocks got flagged incorrect and it should start us with both lab parts, but not the labs themselves until wood tech completes.

Console workaround. /c game.player.insert{name="lab", count=1}

This will drop a lab into your inventory, which picking it up will complete the tech. Should be a way to do it just for the construction cores, but you'd need the internal name for the cores which I do not have.

the workaround does not work because you need to craft it.

edit:

ok you need to take into your hand