Absolutely true. Running the chain & rings until they're both shot is the most cost effective approach, and can be made more so by using the more inexpensive chains and steel rings.

A sync chain and rings are about as low-tech and low-demand as any chain drive you'll find on a bicycle in that they only handle the captain's power (+ any drag from a stoker who's not as efficient as they could be) using a 1:1 ratio. In this respect, they'll outlast a fixed gear bike chain by at least an order of magnitude and even the most poorly maintained chains don't significantly impact performance so long as they don't become loose enough to derail.

Anyway, I think it's fairly obvious that I'm a bit particular about maintaining my equipment and I've just never been able to bring myself to knowingly use a chain that has worn to the point where it begins to accelerate wear on a chain ring or cassette cog. The other little nuance with sync chain wear for me is that I'm overly sensitive to riding position changes. As that chain wears the eccentric begins to clock around, raising and moving the front bottom bracket. Dumping the chain at a normal wear interval curtails fit issues for me as well.

So, my personal solution isn't necessarily what I'd put into a tandem maintenance manual for general consumption.