experiences as SME / expert witness on patent litigation

[aprof]

Hi all - does anyone have experience as a subject matter expert / witness on a patent case?  Recently received an inquiry about this, but not sure how seriously I want to consider it.  I've heard the pay is good but the work can be frustrating, in terms of sorting through legal minutiae that don't make a lot of sense with respect to the underlying science.  However, this is really just a single data point, so I'm wondering if anyone else has experience with this.  How was it?  Would you consider it again?

Also, I'm in STEM and Associate with tenure at an R1.  I'm not incredibly anxious to reach full status imminently but I also don't want to pour weeks of time into something that's not advancing my research or teaching me something useful.