Yes. There is someone who knows and there is also a chance to edit something to try out larger connection amounts.

If every user had 100 ultrapeer connections or if every user had 3 ultrapeer connections would not change the individual search horizon (in theory at least, in the real world the network would collapse in a second). Now if most people have 3 connections and some have 100 connections those with many connections would have a much bigger search horizon reducing the search horizon of all others. - That's why I as a responsible person, am not going to tell how to do it.

However, I will give you a hint, - the answer is in the source code (only some 140.000 lines of code - to discourage you as much as possible).