In latest version 3.22, you can always edit offset range (station numbers) and time window (msecs.), in Trace menu gather displays, with ALT+P.

Once you change these limits, offset zooming (Shift+F1) and/or time zooming (F1) is disabled.

In Trace|Shot gather display, uncheck Processing|Edit offset range / Edit time window, to restore zooming. See our latest release notes.