effects most with C, Cis , B notes. .. 
There’s no one part of the reed that, in general, determines the character of individual notes.
The top of the staple can have a strong influence on the relative tuning of B and C - but you have to consider the system as a whole.
- Bill
Not really a direct answer to your question, but you might read [PDF]
Vibrational Modes of an Uilleann Pipe Reed - Tuftl - Tufts University. Just google the paper title. This has to do with studying a form of
Chladni Plate vibrational modes. While there is certainly some technical detail, there are more than adequate illustrations and diagrams for you to get the drift. I wish there was more work being done in this field but it is an expensive proposition.
BOB