The uncertainty is diminishing as the Scientific understanding improves, and things may turn out to be a little worse than previously thought ...
Well, recent research hints at an answer as Science gains a better understanding. It's likely to have a slight negative effect, resulting in less cooling.
In complex systems involving significant time scales there are often
hints about various causes, and various degrees of
'likelihood', but usually little certainty.
I prefer to base my opinions on sound evidence which can be demonstrated with repeatable experiments, such as the evidence that increased levels of CO2 increase the growth of most plants.
As science progresses and gets a better understanding, what was previously accepted as being true is often found to be false. A couple of recent examples, which involve significant complexity, is the human genome, and the rate of expansion of the universe.
When the human genome was eventually sequenced, only the protein-coding genes, representing 1 to 2 % of the entire genome, were considered to be relevant. The other 98%, or more, was viewed as 'junk DNA', a left-over from our distant evolutionary past which no longer served a purpose.
This view is now considered to be false. Likewise, the expansion of the universe was considered to be slowing down, a view endorsed by the late Stephen Hawking, until more recent observations from the Hubble telescope revealed that the expansion of the universe is actually accelerating.
It wouldn't surprise me if the claimed main cause of the current warming, anthropogenic emissions of CO2, will eventually be found to be false. I have an open mind, unlike some people who unwittingly accept a fabricated consensus designed to create alarm.
I did some more internet searching for recent studies on this great uncertainty about the effects of water vapour and clouds, and can find no resolution which you suggest is occurring with recent research.
Here are some very recent studies:
https://www.nature.com/articles/srep41475 (Sancho-Lorenzo et al (2019)
"Clouds affect the global energy balance as they reflect a large fraction of the Sun’s incoming radiation and at the same time absorb and emit longwave radiation. Despite their relevance, large uncertainties remain with respect to the response and feedbacks of the clouds to anthropogenic forcing. Consequently they are considered as one of the main sources of uncertainty for climate sensitivity and future climate scenarios."
https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JD030150 (Hentgen et al (2019)
"Although crucial for the Earth's climate, clouds are poorly represented in current climate models, which operate at too coarse grid resolutions and rely on convection parameterizations." https://link.springer.com/article/10.1007/s40641-019-00126-x (Nuijens and Siebesma (2019)
"Clouds in nature are more complex than the idealized cloud types that have informed our understanding of the cloud feedback. Remaining major uncertainties are the coupling of clouds to large-scale circulations and to the ocean, and mesoscale aggregation of clouds."https://journals.ametsoc.org/doi/full/10.1175/JCLI-D-18-0417.1 (Ying and Thompson (2019)
".. there is still considerable uncertainty about the underlying mechanisms, whereby CRE (Cloud Radiative Effects) govern the jet response to climate change."I think the very vague term, 'climate change denier', needs redefining as follows:
A 'climate change denier' is not one who denies that climate is changing, or one who denies that human activity has at least some effect on climate, but one who
denies that there is great uncertainty about the significance of the proposed causes of the current change in climate, which is usually focused on CO2 emissions.
