OK, I had a chance to review the whole thread. Some of my comments from yesterday were not quite on the mark.
In the first round of discussions, the issues were that (a) wet venting the shower is fine looking at the plan view, but is hard or impossible giving the vertical space available. In that you have 9" joists, and the horizontal drain is traveling 16' through the joists before reaching the shower, so the horizontal drain is going to be too low for the shower trap to comply with the trap weir rule while not sticking through the drywall below. And (b) the tub/sink drain connection was using a san-tee on its side rather than a combo.
Part (b) is fairly straightforward, you just need to redo that connection. This assumes that the tub trap arm from the trap to that san-tee on its side doesn't fall more than one pipe diameter, or 1-1/2" if you have a 1-1/2" trap. And the tub trap should all be solvent weld, no unions or slip joints, unless you have an access panel to get to those unions or slip joints.
As to (a) you said you were going to dry vent the shower, but in yesterday's post the issue is how to run that dry vent. The red line doesn't work. Is the yellow line actually present, or something you propose to add? It's not required to be added, and it doesn't directly help you vent the shower. That is, since the shower would be joining the 2 sinks and the tub coming from upstream, and also hit the WC downstream, all before hitting the stack, putting a vent on the stack doesn't work for venting the shower. Too many fixtures involved (common venting is limited to 2 fixtures).
Now if you can run the shower drain separate from the sink/tub/WC, at a higher elevation, and you hit the stack with a separate san-tee above where the sink/tub/WC hits the stack, and the stack has a vent off the top that follows the yellow line, that works to dry vent the shower. I'm a little unclear if the elevations would allow that to work. A variation on this is to have the shower and the WC join and go to the vented stack as the highest fixtures connected, and then bring the tub/sinks into the stack lower.
Another option would be run the shower drain separately to the wall with the stack, but if you don't have room to stack san-tees on the stack, the shower trap arm could hit its own san-tee to the side, with the dry vent rising up to join the yellow line, and the drain dropping down to join the stack lower in the wall below via a wye.
You could also run a dry vent up the shower valve wall and then across what is currently an opening that goes to the ceiling by enclosing the top of that opening. Assuming I am interpreting correctly that the left side wall of the corner with the tall blue level leaning in it is in plane with the shower valve wall, which maybe it is not.
Lastly, you'd have to carefully check the elevations, but it might be possible to wet vent the shower by splitting the sink drains as in the drawing below. [I.e. the separate left hand sink drain would follow a route close to the red vent line in your picture from yesterday.] Green = 1.5", Blue = 2", Red = 3" and I am just showing minimum sizes. Each sink is dry vented by a 1.5" vent denoted by the circle; those vents can combine at a height at least 6" above the sinks. Then each sink drain can run through the floor framing as a 1.5" wet vent (although on the left you could reuse the 2" run you have). The right hand sink drain might end up high enough in the joist bay to allow wet venting the shower trap. It would be close--if the floor is level, and the hole through the first joist is 2" (clear) down from the top of the joists, the sink center line is about 6" above the ceiling at that point. After 8' of run, that's 4" above the ceiling. If you use a low profile shower trap, it might work out, or you might be shy 1/2" of elevation.
Cheers, Wayne