I process each sheet for a different development time using BTZS methods, so keeping track of exposed film can be a tedious affair.

I fill an empty film box with 4x5 sheets of matboard from which I have removed any loose bust or burrs. I unload the sheets into the box and place a mat board spacer after every 6 sheets. I can process 6 sheets at a time so that is convenient for me. I keep notes of the processing time for each sheet in the order in which I place the sheet in the box. Takes some organizing but works well.

In the darkroom, I start at the top of the box and develop six sheets at a time until finished.