Using numeric notation because I’m too lazy to copy and paste a million arrows, the best you can do is:

321463214 ppp.

You can start from down forward rather than forward, but you need to hit both backs, the forward, and the down. I haven’t even seen it work before while skipping the diagonals, so the first forward is the only direction you can skip. Honestly, I find double half circle moves to be the hardest motions in the game due to their strictness. 720 had a million ways to do (I used to do 63214741236 ppp for walkup 720, or 1236987412369 from block).

I found the motion oddly nonuniform with other shortcuts in sf4. Double qcf ultras allow you to skip the first forward allowing motions like 23236. If double hcb motions allowed the first back to be skipped it’d be much easier. Also, if it was double hcf it’d be easier since you’re likely using U2 as a -1 punish and therefore doing it from a downback position anyway.