I would just be cutting out the wet vent section of that!? Then it would just be a matter of pushing that vtr up as high as I can in the bay to bring my branches in and keep them in bays. I could switch all lavs over to two inch drains and tub two inch, two inch trap with bushing ? or 2 line with 1 1/2 trap. Either way I could get a few lines in on it and I’m 3” for what at most 5 or 6 dfu. And I think I can do both wc with one 1 1/2 under IPC.
And that 3 inch keeps me vented until it hits my horizontal main, it works....now just tying the two wcs together so they both use same vent just getting that one over the stack fitted right to share common vent with the other And tying it into stack.