Settings GUI: Label sprite_zoom_min as should be left at default

src/lang/english.txt

@@ -2243,6 +2243,7 @@ STR_CONFIG_SETTING_ZOOM_LVL_OUT_128X                            :128x
 
 STR_CONFIG_SETTING_SPRITE_ZOOM_MIN                              :Highest resolution sprites to use: {STRING2}
 STR_CONFIG_SETTING_SPRITE_ZOOM_MIN_HELPTEXT                     :Limit the maximum resolution to use for sprites. Limiting sprite resolution will avoid using high resolution graphics even when available. This can help keep the game appearance unified when using a mix of GRF files with and without high resolution graphics.
+STR_CONFIG_SETTING_SPRITE_ZOOM_MIN_HELPTEXT_EXTRA               :{STRING}{}{}Changing this setting from its default value will cause many extra-zoom/high-definition NewGRFs to display placeholder/incorrect graphics or no graphics at all (transparent sprites). If any graphical problems occur when the setting is not at its default value, change the setting back to its default value.
 ###length 3
 STR_CONFIG_SETTING_SPRITE_ZOOM_LVL_MIN                          :4x
 STR_CONFIG_SETTING_SPRITE_ZOOM_LVL_IN_2X                        :2x

src/settings.cpp

@@ -1773,6 +1773,19 @@ static bool LinkGraphDistributionSettingGUI(SettingOnGuiCtrlData &data)
 	}
 }
 
+static bool SpriteZoomMinSettingGUI(SettingOnGuiCtrlData &data)
+{
+	switch (data.type) {
+		case SOGCT_DESCRIPTION_TEXT:
+			SetDParam(0, data.text);
+			data.text = STR_CONFIG_SETTING_SPRITE_ZOOM_MIN_HELPTEXT_EXTRA;
+			return true;
+
+		default:
+			return false;
+	}
+}
+
 /* End - GUI callbacks */
 
 /**

src/table/settings/settings.ini

@@ -81,6 +81,7 @@ static int64 LinkGraphDistModeXrefChillPP(int64 val);
 
 static bool LinkGraphDistributionSettingGUI(SettingOnGuiCtrlData &data);
 static bool OrderTownGrowthRate(SettingOnGuiCtrlData &data);
+static bool SpriteZoomMinSettingGUI(SettingOnGuiCtrlData &data);
 
 /* End - GUI callbacks */
 
@@ -4384,7 +4385,7 @@ startup  = true
 [SDTC_VAR]
 var      = gui.sprite_zoom_min
 type     = SLE_UINT8
-flags    = SF_NOT_IN_SAVE | SF_NO_NETWORK_SYNC | SF_GUI_DROPDOWN
+flags    = SF_NOT_IN_SAVE | SF_NO_NETWORK_SYNC | SF_GUI_DROPDOWN | SF_GUI_ADVISE_DEFAULT
 def      = ZOOM_LVL_MIN
 min      = ZOOM_LVL_MIN
 max      = ZOOM_LVL_OUT_4X
@@ -4392,6 +4393,8 @@ str      = STR_CONFIG_SETTING_SPRITE_ZOOM_MIN
 strhelp  = STR_CONFIG_SETTING_SPRITE_ZOOM_MIN_HELPTEXT
 strval   = STR_CONFIG_SETTING_SPRITE_ZOOM_LVL_MIN
 post_cb  = SpriteZoomMinChanged
+guiproc  = SpriteZoomMinSettingGUI
+cat      = SC_EXPERT
 
 [SDTC_BOOL]
 var      = gui.population_in_label