z-edit is still available on GitHub by matortheeternal. It has not been updated since November 2022 but seems to still work. Not sure about Next Gen FO4. I still run Pre Next Gen.
It has a portable version just like MO2. Just extract and place it somewhere. I put mine in the folder where I keep MO2. I am not sure about running with Vortex but with MO2 you run it within MO2 as an executable.
Launch z-edit in MO2. Ensure game path is correct. Should be there already. You need to select Fallout 4 or add profile to z-edit if it does not exist. I think it will default to Fallout NV. z-edit works with FO3, FONV, FO4, Skyrim, etc.
Select zMerge. It will default to zEdit. Create name of plugin. I add Merged to end so I know it is the merged plugin.
I used Clean (New) for merge method. Click on Plugins tab and select your plugins to merge. I did tactical flashlights just now as it only has two plugins.
Click OK. Click Build Merge. Wait for merge. It should pop up with window that says Merge Successful. Close out window. Close out z-edit.
Your plugin should be in a folder called merged inside of your z-edit folder.
Zip up newly created merged plugin folder and reinstall in MO2. Place below the mod you just merged. In this case Tactical Flash Lights.
Ensure original plugins are disabled. You can click on them an hide them in MO2.
Ensure new merged plugin is enable.
Ensure plugin load order is still correct.
Test mod out in game.
You can also merge the new plugin into the original mod folder if you don't want two folders.
I kept mine separate so I can easily enable the original plugins again in case it does not work in game.
I was able to find tactical flash light at the chem station, so it looks like z-edit still works.
Not all mods are good candidates for merging. Clothing is normally OK to merge if it the mod does not have a lot of dependencies.
Vtaws Mods should be OK. I have all my Vtaw mods merged into one plugin.
No need to merge light plugins.
z-edit the tool contains zEdit, zClean, and zMerge. I just use the merge portion. Use FO4 Edit for the rest.
I would do your merges when testing out your game. You will have a bunch of missing plugins that are burned into a save. Could cause problems.
When you go to play for real, start a new game. I use a vanilla save file (No Mods in save) for that.
You can redo your character in Looksmenu once game loads. Just ensure you save your character as a Looksmenu profile.
This way if you end up starting the game over multiple times during mod installation you avoid having to create your character preset again.
There are vanilla saves you can get here. I use one that has saves at multiple parts of the game. You don't need to start out in the vault every time and is safer when using mods anyway.
If you load the mod cheat terminal you can use that to access Looksmenu from your Pip Boy.
https://www.nexusmods.com/fallout4/mods/13285