Mantella does not come with native start up built in like a "simple" .dll - Mantella is a beast, it is raw power that requires you to be absolutely sure whether you want to merge with its stunning reality. No I am not making fun of the functionality of this amazing tool, I mean it - it is great that you can start Mantella depending on whether you need it or not, because it produces a lot of files on your disk while running and also could impact performance and sometimes you don't need two whiterun guards commenting the Dragon Fight while your machine barely can handle all those fingerlicking Khajit-8K body overhauls. But for real, if you want to start Mantella on Steam Link you either need it to start as a custom Steam App, use a mouse without Big Picture Mode or start it in any other complicated way. I made it comfortable for you so that you can just start Mantella (minimized) with Skyrim and close it (and its requirements that are running also on the side), that's it. It is simple and you only need to change 2 lines in the bat you can download:

Installation

1. Download the file manually, drop it somewhere, I recommend to put it in the Mantella file directory or in your Skyrim Steam Folder, maybe you forget about it and you want to backup your Skyrim Deployment at some point. That way it sticks where your Mods are.
2. Right click and Edit the .bat file (unpacking it or downloading it might alarm your anti-virus because it is a .bat and these tools commonly label bat files as potentially harmful. Make sure you find a workaround depending on your OS and anti-virus to get access to the .bat in the zip folder you download here.)
3. Change the lines where I replaced the archive structure where the tool will scan for executables with "YOUR_FOLDER_STRUCTURE" to something like "G:\SteamLibrary\steamapps\common\MantellaSoftware\" -> this is my own Mantella installation, I placed it into the Steam folder next to Skyrim Special Edition on my external drive. Just make sure it matches your own path.
4. (Optional) If you use a mod like Custom Window, make sure the name of the program in the second line matches your Skyrim application window title -> set progToWaitForTerminate=YOUR WINDOW TITLE
5. Open Steam and add the .bat as a custom game. (Open the link for a official steam tutorial on how to do it, it is simple and fast, in case you never done that before)
6. (Optional but highly recommended) Change the game icon by going into the proprties of the custom game you added to your library. There you can change the icon of the new app - also change the custom logo by right clicking on the application header in the library once you selected the game. I put 2 files in there that I am personally using. If you want more icons I can make new ones, just let me know. (Maybe a combined mantella and Skyrim logo for example, idk). You can use the .ico files to also change your SkyrimSE.exe icon if you want.
7. Launch the game while you are in your living room, have a glancing BIG PICTURE MODE in front of you and enjoy! Have fun <3 

All Credits for Mantella go to ArtFromTheMachine for making this mind blowing App! Seriously, ENDORSE IT or I will stuff sweet rolls in your mouth while you sleep!!!




Unrelated but maybe useful: Load Order Issues in General?
I created a snapshot of my latest modlist as a collection. You can use that to look up where I placed mods you might also use. This modlist contains mostly very functionally or gameplay orientated mods but also experimental combinations that require manual patching. If you need help with mods, feel free to contact me! <3 Happy modding, cheers ~