Jelqing SD seems more effective?

I mostly do “squeezed jelqs” where one hand clamps at the base while the other does the movement. Well oiled, of course. Alternating hands every few minutes. Though I occasionally switch it up with regular non-squeezed jelqs for a few minutes here-and-there.

I’ve tried different angles like slightly downward or straight out but lately I’ve been trying them SD (well, as close to SD as I can get) because I’m trying to stretch that dorsal cord like a BTC stretch.

I notice that there’s much more blood engorgement when I get to the head when doing it this way. (SD)

Why? Is it because the downward bend is more effectively preventing blood escape compared to having it slightly downward or straight out?