Canonical has released Ubuntu 20.04 beta on 16th. It should be the same to the final version, rest of minor bug fixed. Software version and kernel version are frozen, and the rest I can't imagine to be too far off.
I'm glad to report that it runs near-perfectly on ThinkPad X1 Gen 7 with 10th-gen Intel CPU.
Rest of fingerprint sensor and LTE, all peripherals work, including Thunderbolt 3 and beam forming microphone array, which were didn't work quite well in previous versions.
I'm also surprised to find my 10GbE AQC107 NIC works out of the box, so far I've not seen much of an issue.
There are issues related to Thunderbolt 3, namely partial device enumeration, but I take that it is a use land bug as devices can show up, just not working properly. Replugging in devices solve the problem without needing to modprobe.
HiPDI support is wonderful, way better than Windows, which is the reason I tried it in the first place. KiCAD and LibreOffice look much more natural than on Windows, and are significantly faster.
Media-rich web pages suffer from performance hit more than on Windows, which is the only performance hit I've encountered now.
Youtube and Gmail random color bad pixel bug (introduced to 4K ThinkPads from Win10 1910 to current) doesn't seem to affect Ubuntu.