1.Lee did pass through the sand with 5 gates.
2.Lee being stronger then he was before will go through the sand with more ease given the fact that psychical energy is raised with training which raises the raw strength sand speed of his gates.
3.Heat turns sand into glass.
4.He only loss because the pain was intolerable and he closed his eyes for a second.
If he did the same moves now he would be able to endure until his assault was finished.
Am i saying he will win outright ? No,gaara has gotten stronger too.
Although,you did need to be corrected,sorely.
1. Lee didn't pass through his sand armor. So he won't be able to suddenly do it.
2. So gaara isn't stronger...? He manipulates a lot more sand a lot easier. What says his sand won't be harder to break through?
3. Except it's manga fact fire doesn't work on gaara's sand..? so...
4. You're talking about hidden lotus. Gaara can cushion the fall with his gourd. 5th gate he pounded gaara the hardest he could, gaara's sand armor didn't break and gaara still cushioned the blow with his gourd.
We are talking chuunin exam Gaara VS Chunin exam Neji. Honestly this fight could go either way at least until Gaara goes cloak mode anyway. Gaara's sand is powerful yes. But Neji is not Lee. Rotation would probably repel most of Gaara's sand assault. Jyuuken (Gentle Fist) don't forget that Neji can tag tenketsu and shut Gaara down from using his sand jutsu. The only real issue is the autodefense from Gaara's sand in the gourd.
Neji's Byakugan can see the chakra pathways so when Gaara is about to launch an attack Neji can react accordingly and shut him down. But again once Gaara goes Shukaku mode...well I think it's all over for Neji.
You said neji can block the sand. Fair enough, no one denied that. But you never said how he gets through it; instead, he somehow shuts off gaara's points out of the blue? Neji has to get through auto defence, then sand armor just to pour his chakra into gaara.
Not like neji ever passes auto defence anyway because it happens without gaara's input. That means no matter how hard neji looks, he won't see when auto defence will activate, since gaara doesn't control it... neji needs brute strength or speed to even have a remote chance of winning this. He has neither.