RStudio taskbar font too small

Hello, I'm using RStudio 1.4.1103 on a Ubuntu 20.4 machine with the i3 window manager installed. I've been struggling with font sizes on graphical applications, namely those dependent on qt5 and GTK, but managed to fix those by using qt5ct and editing both .gtkrc-2.0 and gtk-3.0/settings.ini. RStudio's taskbar, however, doesn't seem to be respecting my font size configurations. If I open a window like Global Settings for example, the font size is actually fine. But the taskbar itself is impossible to read. Any change I make to the GTK files or through qt5ct, lxappearance or xfce4-appearance-settings seems to make no difference. I've tried messing with ~/.config/RStudio/desktop.ini, which looks like a qt5 config file, but haven't been able to find the correct syntax for the font size I'm trying to change. Here's a screenshot of the issue:

I also have gnome installed (it comes by default with the standard Ubuntu installation) and KDE Plasma, but I'm only using i3 as my window manager.