How can I reinstall Ubuntu focal 20.04 on an existing LUKS encrypted system?

Based on the my personal experiments using the Ubuntu 20.04 installer, online research, and asking various forums (and lack of answers there), I conclude that as of today, there is no way to do all of the following:

• Installing/reinstalling Ubuntu ...
• using the installer GUI ...
• on a pre-encrypted system (LUKS, with separate /home partition or not) without destroying pre-existing personal files...
• with dual booting another OS.

Of course there are ways of doing this if you rely on the command line, which I was looking to avoid. I've decided to switch to Fedora 32 as it meets all these requirements. Ubuntu served me rather well for over a decade, hope to return when the above issue is fixed.

For those interested in my Fedora 32 setup:

• Dual-boot setup with Windows 10.
• Reuse (DO NOT FORMAT) /boot/efi partition from Windows 10 install
• Create UNENCRYPTED /boot partition
• Create/Reuse ENCRYPTED / partition
• Create/Reuse ENCRYPTED /home partition
• Provide Passphrase to unlock above encrypted partitions.
• Post install, added RPMFusion repository and Gnome Tweaks extension

Thats the summary, its been a week and so far things have been great with Fedora 32. I've not really noticed much difference from Ubuntu for my needs (Email, Browsing, viewing photos/videos, music, skype, spreadsheets, documents).

Thanks!