 512mib is fairly enough I think. (re @troyBORG: How big do you guys usually make your UEFI partitions.  Or do you usually just go with whatever the defualt is?)
[08:04] <guiverc> @theNewOrder, I can't remember what the default was/is, but I've often gone larger than default for a few boxes used only for QA-testing (thus a number of installs are put on it); I used default for boxes I use though
[08:05] <guiverc> sorry I may have misunderstood who was asking ^  (I've had issues on boxes with multiple installs thus larger for QA test boxes where I know it's likely I'll install a number)
 reported a new/strange bug https://bugs.launchpad.net/ubuntu/+source/syslinux/+bug/1937115 seems to only affect Dell machines - great if someone could test/confirm this -