You're right. Super-pollutants like methane, tropospheric ozone, black carbon, and hydrofluorocarbon have up to 2,000 times the warming potential of carbon over a 100 year time scale.[264], [265] Advanced economies can investigate good mitigation strategies and pay emerging economies to phase them out as soon as possible.

However, the overall funding gap is likely much lower (perhaps in the hundreds of millions) than for clean energy R&D (which is in the tens of billions) and so diminishing returns will set in earlier. Thus, while investing in this is quite cost-effective, there is an upper bound on the benefits (low benefit-costs).

citations here: https://lets-fund.org/clean-energy/