Regarding recent changes to the Light Shield... While the potion effect may be good for balancing, I don't agree with the seeming change of no longer being able to block projectiles.
Before either update 1.0.5 or 1.0.6, I was able to be pretty well protected from arrows, snowballs and Ghast fireballs (Ghast ones still get reflected, though Blaze ones never were...). Now, I get hit with them no matter what.
I propose that the shield be able to, if not destroy the projectiles, reflect them. I'd particularly love to be able to use the shield to get close to skeletons and Blazes.
It always felt kinda exploit-y that you could use the shield to protect yourself from fall, hunger, poison, fire, or pretty much any other kind of damage (Besides maybe aiming the shield down when walking through fire), so that seems like a good change.

One other issue is that I've recently found myself going through ceilings when using Jet Engine. It's pretty easily replicable by having a one-block-thick ceiling, and aiming the Jet Engine destination point so that it just avoids touching the ceiling, and you should fly straight through.

As a sidenote, it would be neat to be able to choose the distance you teleport to, particularly with Penetrate Teleport, using the mousewheel or something. I know you could be very careful with your timing, and that might actually be more rewarding, but it's just a small suggestion.
It would also be cool to be able to protect entities behind a shield-wielder from damage, but I'm going to stop now because it feels like I'm just making suggestions now rather than reporting issues.

①the Light Shield actually works after testing.
②Using mousewheel to control distance is an excellent idea ,I'll work it out.

Do you mean it's able to reflect projectiles? I tested it on Blaze fireballs, Arrows, Ghast fireballs and Snowballs, and only the Ghast fireballs were reflected; the others seemed to pass through unaffected.

Reflect proectiles -> Vector Reflect.
Light Shield can only pretend damage from them.

Does that include effects delivered by them? For example, if I put a light shield up while fighting Blazes, should it prevent me from catching fire as well as protect me from direct damage?