still bothered by that one Verbatim BD-RE DL that burns fine on my $100 portable blu-ray drive, but consistently chokes around the layer transition on my $300 desktop blu-ray drive. IF THERE WAS TO BE AN ISSUE AT ALL, it should be the other way around, right? Like it would totally make sense if the $300 drive burned more reliably than the $100 drive, that would be logical. But nothing about Computers is ever logical.
After perusing Redfox and ImgBurn forums extensively, I have learned A Thing. Apparently, a part of the recordable blu-ray spec is "spare areas," which is basically the same concept we apply with SSDs today - a certain amount of space on the disc can be set aside, so that if write errors pop up, those bad writes can be remapped to the spare areas. All reports seem to indicate this is handled seamlessly enough that it doesn't impact video playback. As another caveat, not only do you lose space, but in order for your drive to properly implement the spare area concept, burn speed is halved, as the drive continually verifies writes as it performs them, so any write errors can be immediately remapped. So a 2x burn will take as much time as a 1x burn, or possibly even slower. This can balloon burn times pretty absurdly, as I've seen reports that burns utilizing spare areas on 3 or 4 layer discs can take six to eight hours. Imagine that.
ImgBurn, by default, disables these spare areas, which gives you access to the full capacity of a disc. My Verbatim BD-RE DL shows as being exactly 50GB in size. I was curious if enabling spare areas would allow both of my drives to handle this disc without any issues. So I ticked all the correct boxes, and then did what you have to do. A full disc format. Because BD-REs behave like DVD+RWs did, they need to be formatted to be usable - which in both cases amounts to having a blank session written across the entire disc.
A BD-RE DL disc takes 90 minutes to burn at 2x (without spare areas, of course), and a full disc format takes the exact same amount of time, as it has to zero out the entire disc. I performed this full format on the XD07, just to be safe, with the size for the spare area format set to "whatever the drive/disc prefers". The resultant disc was now a 46GB BD-RE DL.
I took it back over to the desktop drive. Loaded up an ISO to test - my latest rip, the BFI release of The Wages of Fear.
It's too big for the disc. The ISO is 47GB. The disc only has 46GB available.

So I go into ImgBurn settings again - this time on the desktop - and switch the format size to "Maximum" which reduces the spare area to as little as is needed, prioritizing usable disc space, and click full format AGAIN, only this time on the desktop.
Last time I tried formatting this disc in the desktop drive, it ran into the same error it always has, around that layer transition. This time... it's currently sitting at 85% formatted (one hour and three minutes after the format started 🙃) and hasn't thrown a single error! I have to imagine the desktop drive is seeing the sectors it dislikes and remapping them to the spare area as it goes. Hopefully this will be the end of issues? And hopefully after this format I'll have hit the sweet spot so I can actually burn most of my dual-layer ISOs to this disc for testing? If this doesn't work I'm gonna give up and stick a label on this disc that says "XD07 ONLY" and try to move on with my life.
Anyways I might be sending out some of the first batch of burned discs this week so if you've asked for one, look forward to that 