If the entire purpose of this exercise is for somebody to fly to China for little or no cost and back, within a fairly tightly prescribed time frame, then a confirmed (refundable) ticket is hardly going to suit the overall mission, even though it might work for purposes of dealing with boarding and Chinese Immigration. At best, the flyer has a chunk of funds tied up in an expensive ticket for a period of time. At worst, the flyer has to use the ticket and the freebie round-trip goes out the window. In high seasons, it's a pretty good bet that no empty space will open up and that purchased ticket will have to be used.

Of course, some would point out that it would be possible to make that refundable confirmed ticket to another regional Asian destination at much lower cost than a TPAC. True. However, if one has to use it, it just shifts to a different location, the problem of getting back. And during heavy travel periods, it's difficult to travel NRSA from ANY Asian origin TPAC, not just China. A one-way back from anywhere, Asia to anywhere, USA isn't cheap even in a lower fare bucket (not likely on short notice). The only people this strategy might make sense for are those with wide open time schedules, who could deploy the ticket to another Asian location that doesn't require an advance visa, and afford time and cost to hang out or travel around for awhile until an eastbound TPAC seat opens up from said other Asian location.