I use nvimpager. I let it use the same config as nvim by using a symlink ln -rs ~/.config/nvim ~/.config/nvimpager.

To not load all my plugins when using nvimpager I have

if not nvimpager then
	-- neovim-packer
	require("load-plugins")

	vim.g.previm_open_cmd = "$BROWSER"
	vim.g.vsnip_snippet_dir = "~/.config/nvim/vsnip"

	require("configure-nvim-cmp")
end

in my init.lua. Though when I open nvimpager I get
/home/dude/.config/nvim/plugin/packer_compiled.lua:8: in main chunk

So I though maybe I need something in the else branch that says "ignore ~/nvim/plugin", but I don't know how.

OK, I've solved it by putting the packer_compiled.lua into the cache directory instead:

local packer = require("packer")
packer.init({
	compile_path = require("packer.util").join_paths(vim.fn.stdpath("cache"), "plugin", "packer_compiled.lua"),
})
local use = packer.use
use("...")

OK, I've solved it by putting the packer_compiled.lua into the cache directory instead:

local packer = require("packer")
packer.init({
	compile_path = require("packer.util").join_paths(vim.fn.stdpath("cache"), "plugin", "packer_compiled.lua"),
})
local use = packer.use
use("...")