Fedora 28 and Firefox 61 - it works, but the UI performance is absolutely dreadful - on an OC'd Ryzen 5 1600 with 3000Mhz DDR4 RAM it takes 5-6 SECONDS for UI to show up after it is clicked. Similar to show flags on the country list. Firefox often offers me the choice to kill hanged-up js script that addon is using.
On the, ekhm, rival browser the UI performance is significantly better, but honestly, still slow. Like 1,5s for UI to show up, instead of 6s on Firefox.