Hiding of #PanelUI-button breaks "new addon installed" popup dialog

[JamiKettunen]

As SimpleFox comes out-of-the-box it hides #PanelUI-button which completely breaks the "new addon installed" popup dialog similar to this one:

It will keep appearing and disappearing constantly very rapidly and follows you to any other Firefox window you may move your focus to until you restart Firefox entirely.

I'm seeing this on Nightly 104.0a1 (2022-07-14) but believe I already saw this on current stable version before as well.

As I personally prefer having access to the button anyway I ended up just applying the following:

--- a/chrome/userChrome.css
+++ b/chrome/userChrome.css
@@ -165,7 +167,7 @@ toolbarbutton.bookmark-item:not(.subviewbutton) {
 #pageActionSeparator,
 #tabs-newtab-button,
 #back-button,
-#PanelUI-button,
+/*#PanelUI-button,*/
 #forward-button,
 .tab-secondary-label {
   display: none !important;

P.S. Please add a trailing new-line to userChrome.css, thanks :)

--- a/chrome/userChrome.css
+++ b/chrome/userChrome.css
@@ -202,4 +206,4 @@ toolbarbutton.bookmark-item:not(.subviewbutton) {
 #context_selectAllTabs,
 #context_closeTabOptions {
   display: none !important;
-}
\ No newline at end of file
+}