All forms of underwater plants will do better with more CO2, especially the ones that also grow above water. Perhaps not including seaweed.

I don't know how much effect that will have, given seaweed is mostly it, but planted aquariums typically need to artificially inject CO2 into the water to get decent growth rates. The exchange rate with air is deeply unfavorable, so there'll be barely any CO2 in the water otherwise.

The exchange rate also worsens as temperature increases. I'm not sure how it'd work out overall.