The GTK fork is great, but it’s so slow - especially on HiDPI displays.
I tried it out on my 4K monitor and I felt a noticeable increase in typing latency. It started to feel a lot more like VS Code.
Ultimately I was about to get HiDPI support working in Xwayland in Sway with a series of patches and I ran Lucid Emacs, which was much faster and made the latency increase go away entirely.
The plan is to get that merged upstream at some point, you can find out more about it on the official mailing lists.