Just for closure on this, I was able to get a resolution to my issue. I had been trying to use the following flag for disabling instrumentation;
disable_instrumentations=dispatcher-servlet
as it seemed the most relevent
However after playing with different combinations of properties for a while, I was able to unmask my methods from the dispatcher servlet by using this property instead;
disable_instrumentations=servlet-api
Unsure of the differences between them, but am happy that I'm able to move on to other elastic setup after spending a while on this.
Thanks for all your help.