Everything in red is existing. I plan to wet vent from the new 3” Vent. That wet vent would end at the toilet prior to the existing 1.5” vent, which is connected to the drain via a 3x3x3 wye and hub, which is inline with the proposed new plumbing upstream and existing plumbing downstream. Would it be to correct to increase the 1.5” Vent size and start a new wet vent for the remaining fixtures downstream? So it would be essentially 2 inline wet vents. IPC code here