Overall = outside edge of retainer to outside edge of retainer.

Columns are always equal — divider bars run down the middle in essentially every real job. Equal split centers row divider bars on equal on-center pitch (overall ÷ count — e.g. 96" ÷ 4 rows = 24" o.c.), and every tenant panel is cut to ONE size — the smallest visual opening found anywhere on that axis, minus 3/16" — so panels are fully interchangeable. Uncheck it to set each row's height directly; editing one row redistributes the rest automatically.

Row dividers are automatic (based on # Rows). Check a row as full width to remove its column divider(s) — e.g. a full-span directory row above/below rows split by tenant.