I so wish I could talk to you via voice as this is a big one I’ve been interested in for years now. That wiki Is exactly what I used. So here’s my thoughts… 
All pedestrian push button crossings in the USA follow this and the reason for marking this is two-fold. So pushing the button tells the light to change. The navigation apps know that when a traffic signal for vehicles is next to a traffic signal for pedestrians that it only treats them as one signal when driving. The crossing node is marked as well as the pedestrian crossing itself just as mentioned in the wiki. Now why would we do this? Timing for pedestrians is seen by the length and type of crossing; timing for vehicles is seen as how many and what type of crossings there are (which is only seen by nodes, they don’t see the line of the crossing.) The pedestrian timing is actually longer when a signal is used instead of a marked crossing as average wait time to cross is increased by a minute for every crossing. It doesn’t matter if the crossing is marked or unmarked at this point. The light has changed and all traffic stops. Typically these signals also include the sound and vibration items mentioned on the wiki page. Also on this page the very first “How to map” states to use this tag for crossings, “regulated with light signals,” which seems to imply to me that this is the primary choice that the wiki editors are recommending to use when there’s a question as to which type of crossings picked. 

The vehicles only see the node of the crossing and never the crossing itself. The signaled crossings also increase travel time by vehicles so the node must be marked and not just the crossing line itself. 

I don’t know if I’ve made a good enough argument but I hope it’s at least good food for thought and I totally appreciate your opinions!