Any way to reverse engineer professional audio algorithms or those in e.g. rack units? Any way to reverse engineer professional audio algorithms or those in e.g. rack units?

In order to study how they're implemented?

Not suggesting to steal ideas, but as education.
Not really. 

Anything that's a linear and time invariant is of course easy to characterize but most pro audio stuff doesn't fall into this category. It's typically dynamic, time variant, non-linear, signal dependent, etc. These types of algorithms are extremely difficult to quantify if you don't know the internal structure and the parameter space. 

Even if you get a full characterization, you may still not learn something about the way it's done. A time-invariant reverb, for example, can be measured through it's impulse response. However, you can't really tell how it's generated (unless it's a convolutional reverb in the first place).