Am I correct in understanding that Start 11 can save or recreate the Windows 10 start menu including tiles
There are several different ways to customize tiles in start 11. If you already use custom tiles there is a way to carry it over using the "static tile image" option. But, the newest way is probably the best way to get custom images. In either windows 10 or 11 themes you can now chose a custom image simply by clicking an icon and then selecting custom image. This feature works for either tiles or icons and can use most saved images from your saved photos ect. It is very easy to find a tile for anything as well. Just google the name of the app with the word "tile" or "icon" at the end and you should get results via images that easily. You can also find cool tiles on deviantart.
What I really like about the latest start 11 update is that the windows 11 theme also allows the custom images on top of just windows 10 theme, that theme deserves some attention as well.