Just chiming in to say that this is a good post, and I don't even have much to add to it.
I quit once I realized that paving over desert ecosystems with huge raceway ponds filled with glyphosate, wasn't solving any problem I wanted solved.
For what it's worth, I think we'll be able to dispense with the glyphosate if we're more flexible about what algae we're growing, and fuzzily select ecosystems rather than strains. That way we're better able to tolerate invaders & other stresses. But that means we're not operating at peak efficiency, which means a larger footprint.
I'm more concerned about how we source fertilizer.
(For context, I'm between jobs, but my last job was as an algae cultivation technician.)