FileOctopus is a file manager built around panes rather than tabs. Two folders side by side or a 2x2 grid live in one window, each pane keeps its own view, and a workspace reopens the whole layout in a click when you come back to a task.

Up to 16 panes per window, a Shelf that collects files from scattered folders for one move, and Compare Folders to see what changed between two trees and sync only that.
Queued copies and moves can be paused and resumed, so long transfers no longer block the rest of the window.
PRO is a one-time $29.99 for one person on up to 2 Macs with lifetime updates and a 30-day refund; a 14-day trial unlocks every PRO feature without a card or account.

The free version stays free after the trial. The Black Friday price halves PRO to $14.99 for four days at the end of November.