IIRC, PSI in the photosynthetic complex comes from purple bacteria, and PSII from green sulfur bacteria, so cyanos (and thus chloroplasts) kind of "already are"

IIRC, PSI in the photosynthetic complex comes from purple bacteria, and PSII from green sulfur bacteria, so cyanos (and thus chloroplasts) kind of "already are" "using both". one presumes the option to use both pigments in the harvesting sense has been sampled evolutionarily.