I couldnt find any tutorials for left side rafters so I thought I'd make one.
The skip is really lenient so you can experiment with a combination of 1 or 2 fireballs, as well as 1 or 2 damage tanks. The lower the fireballs and damage tanks, the harder the skip (not really, i find 1 damage tank to be easier than 2). This flexibility makes up for vengefly spawn, behavior, and knockback rng.
When you reach the platform in the screenshot, you want to do 2 full jumps. With the second full jump you'll move left midair and damage tank the vengefly and get knocked back right. Then pogo, fireball to stall, pogo again and dash into the platform as shown in the first video. In the second video I got really unlucky with the vengefly but I was still able to get the skip (i slipped off but thats beside the point)
Edit: Sometimes the vengefly spawns too far left. In that case, you'll move slightly left with your first full jump to grab its attention, then while still in the air, move back right, do your second full jump, and do the rest of the skip as normal)
1