Since I own several Pioneer drives flashed with firmware released after December 2022, I've been looking for an effective method to downgrade and crossflash them to UHD versions. Until recently, the only person capable of downgrading these drives was Billycar11, who essentially had a full monopoly on the process.
Fortunately, this has just changed.
You no longer need to pay Billy $200 for a downgrade, because Trevor has stepped in and completely changed the situation.
As soon as I saw his post on cdrinfo forum, I contacted him directly. I sent him MakeMKV screenshots of all my drives with firmware released after 12/2022 so he could analyze them. In response, Trevor prepared a test version of his flasher for me, which allowed me to easily downgrade from BDR-XD05T 1.22 straight to BDR-XD06U 1.11 in a single step.
The program is very intuitive, comes with a graphical GUI, and Trevor was kind enough to prepare a Polish language manual as well. He is continuously expanding his database of kernels and firmware for Pioneer drives, so I believe it's worth supporting his work.
He has made his environment available at https://research.trev.bot/, where you can find the beta version of his Windows application. Its purpose is to collect information about the connected drive (model, kernel, firmware, MakeMKV data, etc.) and send it to Trevor's development server.
I contacted him via email at research@trev.bot. I received the flasher and assistance. The program is still in an early testing phase, so if any issues arise, we simply send Trevor the JSON files for analysis.
Below is a screenshot with information about my drive, which I bought some time ago with locked firmware (the previous owner had updated it).
Before:
After:
