Indeed test circuits are the way to go, but as you pointed out the one in the datasheet is almost as complicated… the possible mistakes I could make on a breadboard increase exponentially!
Having said that, I am considering doing this for my batches of LM13700s. Unsurprisingly, someone else has already asked this question at another forum. There is a response by Matthew Skala at the very end suggesting an LM13700 LED blinker off the datasheet. I will probably try this after I finish off the other 5 (!) modules that I have on my desk that need a couple of final touches before they go on the case…