It looks like surface concentrations of SO4 and dust (sconcso4 and sconcdust) are requested in scenarioMIP but not surface concentrations of other aerosol species. I think sconcbc, sconcno3, sconcoa, sconcss should be treated the same as sconcso4 and sconcdust in ScenarioMIP. Likewise for the historical simulation, all sconc* variables should be treated the same (at the moment only sconcso4, sconcss, sconcdust are requested).
I'm afraid sconcbc etc. are not included in the CMIP6 data request. The request is based on the requirements expressed by the MIPs ... I'm afraid I can't comment on why nobody requested these variables.
It looks like surface concentrations of SO4 and dust (sconcso4 and sconcdust) are requested in scenarioMIP but not surface concentrations of other aerosol species. I think sconcbc, sconcno3, sconcoa, sconcss should be treated the same as sconcso4 and sconcdust in ScenarioMIP. Likewise for the historical simulation, all sconc* variables should be treated the same (at the moment only sconcso4, sconcss, sconcdust are requested).