I find the best way to maintain a wet edge with any WB paint on large panelled surfaces is by dampening the surface, for this I use a blue Mirka Microfibre cloth. Rinse under the tap and wring out until slightly damp then wipe over the area to be painted, this also acts like a tack cloth and removes any dust. For larger flush doors I do the top first and then the bottom half so that the surface is always slightly damp. Rinse & Repeat on each area. At the end of the week I put all my cloths in the washing machine with a drop of fabric conditioner and they are good to go Monday morning. For lapping in stiles and rails on panelled doors I give the joint area a fine spray with one of those green fly trigger bottles, this works great!
I know one of my peers, Master Nash uses a pump up garden spray bottle whilst applying Furniture Feelings but I personally find it puts too much on.
I know some decs use a yellow car sponge for dampening down but again I think it puts to much on and can leave tiny yellow fragments on the surface.
Hope this helps, let me know how you get on?