LibreOffice 6.2 manual install — GTK2 instead of GTK3

I’m on Fedora 29 (using GNOME) and I always fallback to GTK2 by running “rpm -e --nodeps libreoffice-gtk3” when installing LibreOffice from the default repositories, but when installing it manually I always have GTK2 by default, not GTK3.

Now, I’ve manually installed LO 6.2 (by downloading it from the website) and I have a GTK3 by default; however, I can’t find a way to remove it (no such package “libreoffice*gtk3”) or force GTK2 in any other way.

Question: How to force manually installed LibreOffice 6.2 to use GTK2 instead of GTK3 (if it’s possible)?

I really want GTK2 because it lets me to easily navigate menus using ALT+[letter]+[letter] (GTK3 anticipates pressing and releasing ALT, and I simply can’t manage that reliably), and, when using GTK2, the controls near input fields and lists (font, styles, sizes) don’t cover the content of fields, so I can read font and style names much better.

Simple search gives Force LibreOffice 5.1.2.2 to use gtk2 instead of gtk3? - Ask Ubuntu.

Start libreoffice with the environment variable SAL_USE_VCLPLUGIN set to gtk:

SAL_USE_VCLPLUGIN=gtk libreoffice