[bitfolk] Upgrading from Ubuntu Server 18.04

Good morning folks, My VPS is on Ubuntu 18.04 and it's plainly time to upgrade. And as I have some time off between Christmas and New Year, I figured I should do it then. I see that there's a few possible gotchas to do with PV/PVH mode and supported kernel compression methods... so I thought I'd ask if anyone's done an upgrade from 18.04 to 20.04, and what tips they have. I was thinking of starting the upgrade, then switching virtmode in the Xen shell before the first reboot. Will that work? Or does it need to be a clean VM boot rather than just a restart for it to work? Or is it better to try to get 18.04 working with PVH (using the HWE kernel) and then do the upgrade? Any other gotchas that folks have encountered? The VPS just runs email (exim4/dovecot) and apache, I don't expect any issues with them, and I'm familiar enough with them that I can fix any oddities that do crop up. It's just the kernel/Xen changes that have me being cautious... Thanks, Phil