Ok. 30 degrees is a 1 o'clock position, which is plausible at z223. But the point is that he is more forward facing that he was at z193. His right armpit has to be to the right of his spine and is nowhere near being 4 inches left of JFK's midline, which is where it has to be for the SBT to begin to work (even ignoring the lack of any alignment of the chest exit and wrist or the wrist and left thigh). You are right that we do not know where the left thigh was exactly but I think it would be highly unusual if his left thigh was on the right side of the jump seat.
At Z193, Myers has Connally rotated by over 40 degrees I'm sure. The HSCA estimated his rotation to be 30 degrees to slightly over 45 degrees. So yes, 30 degrees is plausible at z223. Let's go with that.
ITEK's stereophotogammetric analysis placed Connally as much as 8.6 inches inboard of Kennedy.