By default Firefox had pretty bad touch support for me. E.g. no scrolling or zooming. But this was easy to change.
about:conifg in Firefox and set
Then test this by running the following:
env MOZ_USE_XINPUT2=1 firefox
Change this as the default when starting Firefox.
sudo sed -i "s|Exec=|Exec=env MOZ_USE_XINPUT2=1 |g" /usr/share/applications/firefox.desktop