Do you recommend parathyroid imaging testing for patients with recurrent nephrolithiasis who are incidentally found to have an elevated PTH but who do not have hypercalciuria, hypercalcemia, hypovitaminosis D, or chronic kidney disease?

Yes, but with caveats. The “yes” is because hyperparathyroidism is a surgically curable disease if done by an experienced parathyroid surgeon. The caveat is if previous stone analyses have not shown a substantial calcium phosphate component, the stone formation may be due to other causes and unaffected by parathyroidectomy. Counterintuitively, hypercalciuria should not be expected with primary hyperthyroidism; the effect of parathyroid hormone on renal tubules is to reabsorb calcium. That’s why ...

It is not unreasonable to get imaging but depends on the type of imaging and quality of those interpreting it. I generally don't proceed to imaging unless there is hypercalcemia and hypophosphatemia associated with the increased PTH. There is the possibility of FHH, which causes a misdiagnosis and parathyroid surgery could be very problematic.