It would help if I knew what press you are going to use, the answer is yes, you can add the case activated mechanism to your Inflow, if a case is raised below the Uniflow, the mechanism will dump powder, if a case is not beneath the Uniflow, no powder will be dumped.
There are progressive presses that have separate powder die mechanism, the Dillon uses a powder die that doubles as a neck expander, other presses have a case activated lock out, meaning if there is no case in the shell plate, the mechanism is not activated.
F. Guffey