The SST-70 is way smaller than the 70.2. Here it is in the middle with the 50.2 on the right. You can see it’s also a quad die emitter. Maybe 4 SST-20 dies?
Pic by Djozz.
It’s die size looks pretty close to the xhp35-hd, but with way more output.
Here is Djozz review of the SST-70.