Since debian is moving to dracut and ubuntu is not able to get the workflow they want with dracut they may stick with initramfs tools for a while. I will likely submit my packages directly to ubuntu.
Since ubuntu tracks closely to debian i think most issues are posted in debian sites. there isn't much in the ubuntu tracker about encrypted root volumes. Most of them are about the horrible issues with the installer but Im dealing with after install. I'll create a bug report then submit my code.
Ubuntu Launchpad Bug #1980018 (Cryptsetup-initramfs can't deal with tpm2-device options for root): This is the primary bug tracking the failure of Ubuntu's default toolchain (cryptsetup-initramfs) to parse and pass modern systemd-cryptenroll options—such as --tpm2-device or --pkcs11-device (smartcards)—to the root volume at early boot.
Launchpad Bug #2141233: Tracks requests to allow GRUB to natively read and decrypt modern LUKS2 keyslots using Argon2 KDF under Secure Boot. This includes the canonical developer response explicitly declining to officially support or sign the GRUB luks2 module.
Launchpad Bug #1999345: A related, long-running feature request asking Canonical to bundle the luks2 module into official signed grub2 images. Canonical engineers detailed why the code hasn't passed security muster for global inclusion here.
https://answers.launchpad.net/ubuntu/+source/systemd/+question/708158