I entered "UTC" in Ignore lines which contain at Options - Configuration - Ignore Options - Text, closed the dialog with OK, exited UltraCompare and started a new text compare session by selecting two files in file manager, right clicking to open context menu and clicking on Run UltraCompare with the two selected files. The ignore option worked fine and I could see them also in Session Properties dialog. Also changing "UTC" in the configuration dialog to "XXX" and using Session - New Session - Text Mode resulted in taking over the changed default ignore settings for the new text compare session while the still opened first text compare session still ignored "UTC".
Note: By default the setting Reload sessions previously open on startup at Options - Configuration - Sessions is enabled and therefore exiting UltraCompare after changing the ignore options in the configuration dialog and just starting UC again with the shortcut on desktop or in start menu has no effect on the ignore options on the reloaded session(s). So if you change the default ignore options in the configuration dialog, you have to really start a new compare session via context menu in your file manager, by starting UC from command line with the files to compare, or using command New Session without or with closing first active session.
Just restarting UC with Reload sessions previously open on startup enabled does not result in using changing default ignore options. And if only a single text compare session is loaded and just switching the compare mode for example to Binary (Fast) Mode and immediately back to Text Compare in menu Mode does also not result in using modified default ignore options.