How do I change the size of UI text (and specifically the text size in formula box)

Aging user with declining eyesight here …

I have been struggling to increase the size of the UI elements (icons and UI text) specifically the text box where I enter the formula. (I am NOT talking about the text size in the calc or writer documents I am producing)

I am on Debian Unstable using Gnome Flashback (with Wayland disabled)

~$ uname -a
Linux debian 6.4.0-3-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.4.11-1 (2023-08-17) x86_64 GNU/Linux
~$ dpkg -l | grep libreoffice-writer
ii  libreoffice-writer                                  4:7.5.5-4                            amd64        office productivity suite -- word processor
~$ env | grep X

Changing UI size in Gnome Tweaks has no effect on LibreOffice

Where is the setting for picking the size of UI elements

Based on How do I increase the size of the font in the Formula Bar? and there used to be an item in the above Options page where I could change the Scaling of the UI element; apparently, the option has been removed or moved elsewhere. Can someone help me here …

Your LibreOffice seems to not use a correct VCL plugin to integrate to the DE on your system (GTK?), and instead, runs with a generic gen/X11 plugin, which indeed doesn’t not know anything about the DE settings. Either the correct plugin is not installed, or you explicitly chose the other plugin, like in Choose GUI toolkit for LO session - #2 by luyu.

The manual UI font size settings were removed in later versions, to correctly integrate to the system UI, especially with HiDPI (tdf#101646).

Thanks for giving me hint.

The solution is to do

~$ sudo apt install libreoffice-gtk3

Looks like a packaging issue(?) on Debian side …

I wonder why Debian is not picking up libreoffice-gtk3 by default. My guess is, it is a recent packaging change.

(I was surprised to see that the LO 24.2 development build were well-behaved, but the Debian provided builds were defective.)

How LO 24.2 and LO (Debian Unstable) looks before the change

How LO (Debian Unstable) looks after installation of libreoffice-gtk3

I confirm that with libreoffice-gtk3 LO menu text / icons honour the gnome-tweaks settings.

I confirm what you say here. This is how it looks on LO