I’ve started a spreadsheet with the results of j.hp after a b.throw, dash setup. While j.mk is easier to land in most cases, the benefit of j.hp is that it does more damage and causes longer blockstun.
There are basically 3 different timings, with 2 of them being useful against most of the cast. The first timing is an ambiguous j.hp which never crosses-up, but it can land on either side depending on your opponent. If the opponent holds forward, it will hit against the majority of the cast (whiffs against 7 chars) and it will also either land in front or at the back depending on the char.
The second timing is an early j.hp which crosses up against just under half the cast, whiffs against 4, and is blockable vs the rest. Using this version, you can land an unblockable j.HP vs Gouken, Viper, Guy, Cody and Guile. This version of the j.hp is more likely to land on the same side that it hits
The 3rd timing is a late j.hp that hits in front on most characters (or whiffs). It’s not as useful as the previous two, but it’s OK to use once in a while especially after landing j.mk x-ups or empty jumps. But then again, you might as well just use j.HK as it does more damage. I didn’t record the results of these in the spreadsheet yet.
There might be specific timings against certain chars but I don’t think that’s all that useful to know.
The format of the spreadsheet is what happens if the opponent performs the action in the header of that column. eg. “Hit - Front” in the “Hold Back” column means that if the opponent holds back, the move will hit and Blanka will land in front.
I still have to test j.hk, j.mk and the opponent’s reversal and evade options (this will take a long time), so if you wanna help out, record your results and save them in the spreadsheet (it’s public and I have a master copy so I can just overwrite it if someone fucks it up).