A simple automation I use to real-quick switch between my Nvidia dGPU and my iGPU on Fedora. This is NOT how you are supposed to do it, rather create a boot entry menu that sets the said cmdlines!

nvidiactl.lua

#!/bin/lua

local GRUB_CONFIG_PATH = "/etc/default/grub"
local GRUB_MKCONFIG = "sudo grub2-mkconfig -o /boot/grub2/grub.cfg"
local RD_BLACKLIST = "rd.driver.blacklist=nouveau"
local MODPROBE_BLACKLIST = "modprobe.blacklist=nouveau"
local DRM_MODSET = "nvidia%-drm.modeset=1"

local function enable(current_val)
    local new_str = current_val
    local rd_blacklist = current_val:match(RD_BLACKLIST)
    local modprobe_blacklist = current_val:match(MODPROBE_BLACKLIST)
    local drm_modset = current_val:match(DRM_MODSET)
    if not rd_blacklist then
        new_str = RD_BLACKLIST .. ' ' .. new_str
    end
    if not modprobe_blacklist then
        new_str = MODPROBE_BLACKLIST .. ' ' .. new_str
    end
    if not drm_modset then
        new_str = DRM_MODSET:gsub('%%', '') .. ' ' .. new_str
    end
    return new_str
end

local function disable(current_val)
    return current_val:gsub(RD_BLACKLIST, "")
                      :gsub(MODPROBE_BLACKLIST, "")
                      :gsub(DRM_MODSET, "")
end

local function get_grub_config()
    local fd = assert(io.open(GRUB_CONFIG_PATH, "r"))
    local str = assert(fd:read('*a'))
    fd:close()
    return str
end

local function get_cmdline(configs)
    local val = assert(configs:match('GRUB_CMDLINE_LINUX="(.-)"'), "Could not parse the GRUB config file for GRUB_CMDLINE_LINUX")
    return val
end

local function write_grub_config(configs, new_cmdline)
    configs = configs:gsub('GRUB_CMDLINE_LINUX=".-"', 'GRUB_CMDLINE_LINUX="' .. new_cmdline .. '"')
    local fd = assert(io.open(GRUB_CONFIG_PATH, "w"))
    assert(fd:write(configs))
    fd:close()
end

local grub_config = get_grub_config()
local cmdline = get_cmdline(grub_config)
local new_cmdline
if arg[1] == "enable" or arg[2] == "enable" then
    new_cmdline = enable(cmdline)
elseif arg[1] == "disable" or arg[2] == "disable" then
    new_cmdline = disable(cmdline)
else
    print "Usage: nvidiactl 'enable'|'disable'"
    os.exit(0)
end

print("Changing GRUB_CMDLINE_LINUX to \n" .. new_cmdline)
write_grub_config(grub_config, new_cmdline)
print("\nChanges Written.")
print("Regenerating GRUB configs: " .. GRUB_MKCONFIG .. '\n\n')

os.execute(GRUB_MKCONFIG)