You should also note that exceed weapons not only increase soft cap of burst, but the multiplier of burst as well. An exceed(S) at SL30 (like the 2nd UE weapons) will give you a 40% burst buff, so +0.4 to the burst multiplier. This makes hp weapon even more redundant.
Another thing is light generally has access to a shit ton of hp. I don't see much point in increasing that even further when that means reducing your general damage output.
On a side note, light meta (yes, you don't have to read further if you aren't concerned by meta teams for f2p or whatever reason) team will become insanely fast in the future, so you want your hero to be as fast as she can get. I.e.: Shingen with spear.