Commonly I extend my node pool up to 30. Hovewer, after some time of regular gameplay I often find node limit reduced to even lower than 20. I happens more frequent than once.
Now here's two things which may matter (you decide):
I always play Dark Souls windowed because of reasons.
When I notice the issue happening and switch to DSCM window by clicking it on the taskbar, it always has the node limit sections active (it has a text input cursor blinking there). Not sure if extending nodes was the last thing I did before switching to the game window, but seems like clicking any other active area of DSCM window (an entry from the node list i.e.) prevents this from happening.
Commonly I extend my node pool up to 30. Hovewer, after some time of regular gameplay I often find node limit reduced to even lower than 20. I happens more frequent than once.
Now here's two things which may matter (you decide):