It's becoming quite popular in the 'Super Mario 64 Speedruns' Discord server so it seems natural to add it to the guide list. I haven't tried it myself but thought of it as a niche speedrun.

Every LBLJ I have seen is always done in the right pillar. So that got me thinking if it can be done in the left pillar as well. The left pillar also has a latch you can grab on to located around the same step as the right pillar. Obviously when BLJing, you move the control stick to the left and not the right. But there are actually a few things that make a Left LBLJ tougher than a Right LBLJ (or Normal LBLJ).

1. The corner you BLJ into is tougher to find as the camera angle is different. The camera angle also makes it tougher to determine if you have enough space to perform an BLJ compared to the right pillar.

2. You WILL need to rotate the camera to the right at least once after you climb into the pillar (regardless of where your camera angle is).

3. After building up speed, you have to move the control stick up slightly and immediately left-down afterwards to get Mario behind the entry door. BE VERY CAREFUL ABOUT THIS as the Mario's location behind the left door is crucial and often overlooked. If you are on the left, you will likely end up either behind the Bob-omb Battlefield or Cool Cool Mountain door. You want to have Mario in the centre or on the right if you want to get successfully past the 8 Star door.

NOTE that I discovered this variant of the LBLJ on the Switch's N64 online version but it should work on the N64 as well as Virtual Console & non-Shindou emulators.

UPDATE: Here is my proof