I thought I would first point out a quote from the article you cited:About CESA:
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Emergency ascent - Wikipedia
en.wikipedia.org
"This procedure is recommended for ascents where there is no decompression obligation, a free surface with little risk of entanglement, and the diver has sufficient breath hold capacity to easily reach the surface conscious.
If exhalation is limited to relaxing and allowing the expanding gas to escape without effort, there should not be a feeling of running out of breath, as the air inhaled at depth expands during the ascent and the lung volume should remain nearly constant.[5]
Please note that this contradicts your contention that CO2 buildup during the dive leads to diver panic.Next, I found a quote following that which has me puzzled.
While in a practical sense there is little difference between a CESA and a "free ascent" (aka Emergency Swimming Ascent or ESA), the technical difference between the two is that in a CESA the regulator second stage is retained in the mouth and the diver exhales through it (in case gas becomes available due to the drop in ambient pressure) while in free ascent, the regulator is not retained or there is no regulator available, and the diver exhales directly into the water.[6]
I have never heard of this differentiation, and I want to caution divers that they should always retain the regulator during an emergency ascent. If you were for some reason to inhale water during the ascent, that would start a reflex that would likely lead to drowning. Furthermore, something that has not been discussed here is that in an out of air situation, the tank is not actually out of air. The regulator does not have enough pressure to deliver air at the present depth because of the ambient pressure. When you get shallower, the regulator will be able to deliver some of the remaining air. Of course, that won't help you if you have discarded the regulator.