GtkFontChooserWidget search results flickering (and typing feels slow)

Steps to reproduce

1. Open GNOME Tweaks' "Fonts" panel, or gtk4-demo's "Font Explorer" demonstration
2. Click the font picker button to open the FontChooserWidget
3. Try to type various search queries from scratch (from an empty search field). I searched for "Inter", "Cantarell", "Source", etc.

Current behavior

It feels slow when typing in the search entry, especially in the beginning of the search string, and the search results list view flickers a lot.

Expected outcome

Flicker-free / fast / non-blocking search.

Version information

GTK 4.14.4 under Wayland on Fedora 40,

Additional information

Opening the GtkInspector and setting a search-delay of 2500 on the SearchEntry widget, it does not seem to be more performant, it still micro-freezes on search (and flickers) while you type each character.

Maybe it's connecting to a signal that is not the search-changedsignal?

Generally, as it is not mission-critical to receive search results ultra fast while typing in that field, and that it would be more important to have non-blocking and non-flickering search UX there, I would suggest considering a 400-500ms search-delay for that specific widget's SearchEntry. It would probably alleviate the problem, and would also presumably consume less power?