Questions about copper reagents in organotin testing?

Questions about copper reagents in organotin testing?
Has anyone done the organotin test? During the extraction process, a protective agent called sodium diethyl dithiocarbamate, or copper reagent, is added. We all know that copper reagent is used in the copper ion test, what is the purpose of this copper reagent used here? Is it to complex the organotin to make it more extractable?

Does the copper reagent not react with tin ions or organotin? There is another question, after the extraction process, we have to add sodium tetraethylboronate derivative to the extraction solution, this derivative will not only derive the mono-substituted, di-substituted and tri-substituted organotin into tetra-substituted organotin, but also react with other metal ions in the extraction solution. the organotin is completely tetrasubstituted and no other metals are derived?

For organotin catalysts, glacial acetic acid can be used as an inhibitor, but a better inhibitor is β-diketones, whose enol isomers form chelates with organotin, thus inhibiting the catalytic effect of organotin.