Oh… yea. You can use only 1 blend by just using material attributes on the material.
Thought you had it set up that way already.
Each function outputs a material attributes. You then can blend the attributes and put the output right to the material.
or breake it, make global changes - x vectornormalws, maskg G x scalar, append, back to displacement, tesswllation multiplier, roughness/specularity change, etc. Then you create the new material attribute and connect again.
Also need an error if it breaks…