Well plants kinda need oxygen too for respiration so I wouldn't necessarily say that oxygenation is bad for plants ^^; I was wondering if you know why it would be that water disturbance increases oxygenation of water but causes the CO2 to come out? They are both gases diffused in water, you would think they'd both be affected the same way. Unless it's a concentration issue assuming that there's a build up of CO2 in the water and lack of O2 and so CO2 escapes and O2 enters...
and do you know if the DIY CO2 with yeast also affects those plants also (mosses, javas, marimo)
This is my interpretation, please research this all further! Yes, plants absolutely need some oxygen, just like we need some CO2. We can't breathe in pure oxygen (it does stuff to our heads...), and plants can't breathe in pure CO2. However, they actually use CO2, just like we use oxygen. It is the main component that they breathe. When we (and fish) breathe in air, we release CO2. When plants breathe in air, they release oxygen. So how does this tie into the surface agitation being bad for plants? Say you have a fish other than a betta, one that has to breathe from the water, not from the surface like our fish do. Well that fish is naturally breathing out what the plant needs, and the plant is naturally breathing out what the fish needs*. If you add a form of surface agitation then you are removing the extra CO2 that the fish is adding to the water. This is VERY good if you don't have plants, as the CO2 build up could kill a fish. However, in a planted tank it is less beneficial for the plants. How much CO2 do betta fish add? I have no clue. Any notable amount probably comes from their decaying waste/fecal matter, not from their actual respiration. Though it is not to say they don't add some. I don't know a lot about betta respiration other than they have a labyrinth lung.
As for the DIY CO2, it is a form of natural CO2, thus it will not cause the problems to mosses and algae seen with artificial CO2.
*It should be noted that plants only do this during the process of photosynthesis. Some people do provide a form of surface agitation in heavily planted tanks at night, particularily if CO2 injection is involved as that is when CO2 levels can get deadly as the plants are not removing it from the system. Adding any sort of CO2 should not cause this problem in a planted betta tank as they do breathe from the surface. In particular, DIY CO2 is generally considered the safest and one should not worry about overdosing it unless they are adding multiple soda pop containers to one tank under so many gallons.