Open MakeMKV → Go to Info → Check the "Firmware" line. If it says 1.00, you are on the hot version.
Firmware 1.00 does not have the power-saving restrictions found in later updates (1.01, 1.02, 1.03). The OEM firmware assumes the drive is inside a well-ventilated laptop. When used in an external USB enclosure, the laser diode runs at higher current, generating significant heat.
Do NOT use the stock LG 1.03. You need the "MK" (MakeMKV patched) version. Search for the SDFtool Flasher (available on the MakeMKV forums). Inside the tool, you will find a pack of firmware files. Look for: bu40n 100 firmware hot
You want to stay on firmware 1.00 because it works perfectly with MakeMKV. You are torn between a hot, functional drive and a cool, crippled drive.
Here is the truth: You do not need to stay on 1.00 to get full LibreDrive functionality. Open MakeMKV → Go to Info → Check
Later firmware versions (1.01, 1.02, 1.03MK) can be cross-flashed to a "patched" version that:
Scouring the MakeMKV and Reddit r/makemkv communities, the consensus is clear: Scouring the MakeMKV and Reddit r/makemkv communities, the
"Yes, the BU40N on 1.00 runs hot. Yes, it's annoying. But it's still the most reliable slim 4K ripper available. A $10 fan solves everything."
The bu40n 100 firmware hot search is up 300% year-over-year because physical media collectors are returning to discs as streaming services delete content. If you want to archive your 4K collection, dealing with a warm drive is a small price to pay.