Putting around 5 levels worth of APs into HP for the next 5 levels w/o HP-washing?

Out of curiosity, would this be advisable without HP-washing? I've done a pomegranate-load of HP-washing since ...7X or so, I can't recall how much I spent. But at this point, I no longer feel compelled to spend near 3 dollars per AP resets... >_> As far as I can see, the benefits of HP-washing = Higher HP to HornTail, and that's it. I think the minimum was something like 4.5k (w/o HB) for NLs? Or was it 5k? But I'm only planning to put 5 levels worth of APs into HP from 121-126. If I still don't have near 4k by then, I'll probably do another 5 levels, and so on and so on. I couldn't care less about attack/damage at this point than HP. So if you didn't want to spend NX on HP-washing, would you just dump APs directly into AP?

I'm asking only the Thieves community this, since they know the formula for attack for Thieves very well. I honestly don't think I'll lose too many attack points for 5-10 levels either. Even though that's 25-50 LUK APs.

EDIT: If it matters, here are my stats:

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