At the beginning of summer I made a comparison of BD-R quality variation with MID code CMCMAG-BA5 (HP, Verbatim). The disks were bought in different places, some of them are at least 5 years old.
On the graph there are disks with completely identical recording parameters in spring 2024
Pioneer BDR 205 FW1.12 2x OPC off imgburn
blue - LDC avg (line at 13)
orange - BIS MAX (line at 15)
pichost