Add setting to enable through loading in UI

src/table/settings.ini

@@ -4140,6 +4140,14 @@ strhelp  = STR_CONFIG_SETTING_ENABLE_SINGLE_VEH_SHARED_ORDER_GUI_HELPTEXT
 proc     = EnableSingleVehSharedOrderGuiChanged
 cat      = SC_EXPERT
 
+[SDTC_BOOL]
+var      = gui.show_adv_load_mode_features
+flags    = SLF_NOT_IN_SAVE | SLF_NO_NETWORK_SYNC
+def      = false
+str      = STR_CONFIG_SETTING_SHOW_ADV_LOADING_MODE_FEATURES
+strhelp  = STR_CONFIG_SETTING_SHOW_ADV_LOADING_MODE_FEATURES_HELPTEXT
+cat      = SC_EXPERT
+
 ; For the dedicated build we'll enable dates in logs by default.
 [SDTC_BOOL]
 ifdef    = DEDICATED