Super all-in-one image for comptele noob?

I have a Khadas VIM3 Pro but I may have purchased the wrong device for what I’d like to achieve:

I’d like to connect an external (ext4-formatted) HDD to the USB 3.0 port

I’d like to install CoreELEC 19.3-MATRIX to the eMMC

I’d like to also install EmuELEC 4.3 to the eMMC

I’d like to delete the pre-installed Android instance from the eMMC

I’d like CoreELEC & EmuELEC to auto update themselves

I’d like to have the ability to choose which OS I boot into (a dual-boot menu selector)

I’d like to store all my Kodi media files, video game ROM files, emulated console BIOSes, video game save states on the HDD

I’d like to use WinSCP on my Windows machine to configure both CoreELEC & EmuELEC as needed

I’d like to use WinSCP on my Windows machine to add or remove files from the VIM3 using either CoreELEC’s or EmuELEC’s SSH File Transfer Protocol daemon

Can I do all of this with this device?

Is there an all-in-one image that has all this pre-set? (Wishful thinking.)

Thanks for any help anyone can provide. I think I’ve bit off more than I can chew as I have zero experience with linux; although lots of experience with Kodi on Android TV & RetroArch on Windows.

I’ve cross-posted this to the CoreELEC forum.

Apart from “configuring the box with WinSCP” which is not possible because it’s not an SSH client (use PuTTY not WinSCP) it is all technically possible but neither CE or EE natively support dual-boot via menus from the internal eMMC storage so this would need customised u-boot firmware. All the sources for that are available but it’s up to you to make the customisations; and my personal experience is that users who have the skillsets to do that don’t ask for guideance in forums because they can see how to do it and just get on with it, and the users who ask for guideance don’t have the skillsets needed. It’s a task that needs custom code writing so it’s not something you can do by reading HOWTO guides (that do not exist) or anyone sane will attempt to coach/spoon-feed instructions for.

So choose either CE or EE and put it on the eMMC storage, then put the other on an SD card. When the card is inserted you get one, and when removed you get the other. It’s not all driven by a remote control but it’s practical, low-tech, and will work.

Thank you very much for your reply. It is as I feared. I chose the VIM3 because it, along with the MINIX NEO U22-XJ Max and the Ugoos AM6B Plus all have HDMI 2.1 out. I wanted to future-proof the Kodi box as much as possible and thought that sometime in the future HDMI 2.1’s Dynamic HDR’s SEI messages might be important to CoreELEC and Kodi. That and the VIM3 and MINIX both have unlocked bootloaders which I thought would make using with CoreELEC & EmuELEC easier.

The rest of your points are quite right. I was hoping against hope to mitigate what I am now begining to think was the wrong purchase.

Thanks again for your time on this.