I've been using code editors for over 40 years. I've gone back and forth between Emacs and NeoVim/Vim. The last five years has been extensively Neovim since it is faster than Emacs. On Emacs, I've loved DoomEmacs. It's the fastest on Emacs. I prefer NeoVim over Vim because it is faster (especially when using plugins with Lua or Python). In NeoVim, I've used all the mentioned setups and have settled on LazyVim due to it's starting speed and ease of changing configurations around. LazyVim also requires the latest NeoVim, but it is worth upgrading to it. I use bob to manage my NeoVim versions and mostly I use the nightly version without any hiccups.

VimR (https://github.com/qvacua/vimr) handles Thai okay. Not sure about Burmese. It has to the lastest version also that attaches to the latest neovim build as well. The lastest version also works fine with LazyVim framework (the older version didn't since it was base on a vim library and not neovim.