I noticed that VV uses --headless: https://github.com/igorgladkoborodov/vv/blob/c588d7e3676564bea17b2d526df5db9a6cddb501/src/renderer/nvim/nvim.js#L202

In neovim/neovim#9024 (Nvim 0.3.2) we're considering changing the meaning of --headless. It may not be necessary and may improve behavior if VV uses --embed without also specifying --headless.

Note that the nvim_get_api_info() metadat includes a version field which can be checked to decide whether to use --embed in Nvim 0.3.2+