Updating frame counts to multiple nodes/project setup

Hi, I am a very beginner on Natron (I started using it this week)

Perhaps this question sounds dumb, but updating the frame count became a tedious error-prone task to me for the node structure I built for my project (screen capture attached at the end of this post)

I have 5 read nodes connected one to each other using merge nodes, each one of these read nodes are getting info from a frame sequence (png files), I am generating those files using some external application (some script I made and krita)

Each time new frames are added to the list (the folder), I have to update every one of the read nodes to the new frame count (actually the last frame) and also the frame count of the project, and I think something of the viewer (Like I said I am beginner, I am not 100% how all this works)

backgroundframes

… and also I have to update the project frame count

projectrange

Is there some practical view to update the total frame count of the video without having to do all that?

Just in case the node structure (I think it’s very basic in terms of what natron is capable of handling):