I tried the version for the Pi 3, and it would not boot.
The best thing to do is not use a gui with pi's as every bit of cpu/ram is very important.
Here is a video for a workaround if a gui is needed: https://www.youtube.com/watch?v=okgKiXocZ5w
Yes, in a manner of speaking. You can download Ubuntu server (32 or 64-bit) and put it on a 16 GiB or larger card. Put the card in your Pi 4 and run the initial setup°. Then sudo apt install mate-desktop. You can now download and install MATE or another desktop. Though centered on 19.10, there are several YouTube videos that walk you through this:
° You must connect the Pi with an ethernet cable; Wi-Fi won't work until after initial setup.
I put Ubuntu Server 20.04 on my Pi4 then installed MATE desktop. Now I want to use that desktop from my Win 7 laptop. So I put TightVNCServer on Ubuntu and access from VNCViewer running on my laptop. Have you tried something like this? I also posted this query in another thread but it's not getting any feedback.
When Ivclick on the MATE main Menu, to open it, it closes by itself after about a second so I can't use any programs. Other menus on the desktop work fine, like the shutdown "cogwheel" and the Wifi/Network menu etc..
Have you any experience of this of suggestions?
Sorry for the long delay in responding as I only just saw your post. No, I have not tried to access the Pi with vnc. I usually go in over ssh and/or sftp on that machine if remote access is necessary.
Look into desktopify: https://github.com/wimpysworld/desktopify
Wimpy is going to do another Youtube streaming show today on desktopify today: Hardware accelerated Ubuntu Desktop for Raspberry Pi