If you have set the XFCE scaling and GDK scaling up (to 1.5 or 2 ) you can choose or download a other UI Pack for Libreoffice. Libreoffice support themes that will better match for High-DPI https://wiki.archlinux.org/title/LibreOffice#Theme. For the application unison-gtk I have no idea.
Link how to setup XFCE and GTK3 for high-dpi: https://wiki.archlinux.org/title/HiDPI#Xfce
Hope that helps a little bit.
The Async gem is a beautiful piece of code. I have used its last time often to talk/work with a REST API with the async-http gem and my work was done in 5 mins. Have todo pull/change/update nearly 100k of data over the API and without 'Async' it will have need so much more time to run and build. But yeah the docs are quite small and it's more a try and error, but the developer/users will quickly answer on question at mastodon or github if there are problems or need help. :)