While using Global search in console:
By default it would start searching as soon as you type in any value.
ITMS/SMP 8.7.2.x
Starting from 8.7.3 version it would be changed to controllable timeout value in Core Settings.
Meanwhile for 8.7.2 version you can use attached files to replace default files in "C:\Program Files\Altiris\CustomConsole\Web" folder (rename attached files by removing .remove extension).
Then create new Core Setting item - "ConsoleAutoStartSearchTimeout" which accepts value in milliseconds.
Setting this new core setting to 0, would require Enter input to start searching.