An incorrect monitor is chosen for the top panel blur at session start

[5h4d307]

Gnome Shell version: 45.5
Extension version: 58 (67 most likely affected too)
Setup: 1080p laptop with a 4K monitor connected as primary

Expected result: top panel is blurred across the full width at session start

Actual result: top panel is blurred only to the laptop screen's width at session start

While investigating the issue, I noticed that one of the child actors has the width param set to 1920.
If I toggle the panel blur or the entire extension, everything works correctly (as show in the ER screenshot).

I found that in the current implementation, find_monitor_for() returns an incorrect monitor at session start.
However, the v67 approach w/ findMonitorForActor() works the same way (I made similar adjustments in v58 and tested).

Below is a workaround patch that I'm currently using to overcome the issue.
Nevertheless, I'm not sure whether this solution is optimal, and most likely there are some caveats I may have missed.

Please share your thoughts.

The mentioned patch:

diff --git a/src/components/panel.js b/src/components/panel.js
index 0a335b5..2921b9d 100644
--- a/src/components/panel.js
+++ b/src/components/panel.js
@@ -145,7 +145,7 @@ export const PanelBlur = class PanelBlur {
             panel_box = panel_box.get_parent();
         }
 
-        let monitor = this.find_monitor_for(panel);
+        let monitor = Main.layoutManager.primaryMonitor;
         if (!monitor)
             return;
 
@@ -247,7 +247,7 @@ export const PanelBlur = class PanelBlur {
         actors.widgets.background = is_static
             ? new Meta.BackgroundActor({
                 meta_display: global.display,
-                monitor: this.find_monitor_for(actors.widgets.panel).index
+                monitor: Main.layoutManager.primaryMonitor.index
             })
             : new St.Widget;
 
@@ -317,7 +317,7 @@ export const PanelBlur = class PanelBlur {
         if (this.settings.panel.STATIC_BLUR) {
             let bg = Main.layoutManager._backgroundGroup.get_child_at_index(
                 Main.layoutManager.monitors.length
-                - this.find_monitor_for(actors.widgets.panel).index - 1
+                - Main.layoutManager.primaryMonitor.index - 1
             );
             if (bg && bg.get_content())
                 actors.widgets.background.content.set({
@@ -332,7 +332,7 @@ export const PanelBlur = class PanelBlur {
         let panel = actors.widgets.panel;
         let panel_box = actors.widgets.panel_box;
         let background = actors.widgets.background;
-        let monitor = this.find_monitor_for(panel);
+        let monitor = Main.layoutManager.primaryMonitor;
         if (!monitor)
             return;
 
@@ -362,23 +362,7 @@ export const PanelBlur = class PanelBlur {
         }
 
         // update the monitor panel is on
-        actors.monitor = this.find_monitor_for(panel);
-    }
-
-    /// An helper function to find the monitor in which an actor is situated,
-    /// there might be a pre-existing function in GLib already
-    find_monitor_for(actor) {
-        let extents = actor.get_transformed_extents();
-        let rect = new Mtk.Rectangle({
-            x: extents.get_x(),
-            y: extents.get_y(),
-            width: extents.get_width(),
-            height: extents.get_height(),
-        });
-
-        let index = global.display.get_monitor_index_for_rect(rect);
-
-        return Main.layoutManager.monitors[index];
+        actors.monitor = Main.layoutManager.primaryMonitor;
     }
 
     /// Connect when overview if opened/closed to hide/show the blur accordingly