I've been doing a remodel of my downstairs and have got to needing to plumb in for the sink, dishwasher and washing machine. There is an internal soil stack in the corner of the room which I can plumb into but the old appliances were plumbed into a combined trap under the sink which was just connected with some 40mm pipe straight into the open end of this drain in the floor. Obviously I want to do this more correctly. Can I make a little mini stack of https://www.screwfix.com/p/mcalpine-dc1-bl-drain-connector-black-110mm/4255v https://www.screwfix.com/p/floplast-sp588bl-waste-manifold-black/40832 and cap or something like this https://www.screwfix.com/p/floplast-ax110-black-air-admittance-valve-black/35001 on top to run everything into separately under the sink? or am I just better running some 50mm pipe along the wall into a boss in the stack in the corner?