Yes. TDC1 on the crank and the cams stays lined up even after the car has been started. And the car does start and run through the rev range, it's just that it makes this unpleasant rattling sound -- presumably from the looseness of the belt.

If I had some way to dial in extra tension to compensate, the belt would probably be OK. The tensioning procedure given in the manual just doesn't put in enough tension for this slightly longer belt.

I have heard of a few cases where inexperienced wrenches don't think the belt looks tight enough with the normal procedure, and they push on the tensioner with a thumb to add more tension. For the correct belt, that usually makes it *too* tight, and they end up with belt whine. But this isn't the correct belt -- and so that trick might work just fine in this case. It does mean having to take off the crank pulley and the lower cover.

The other thought was that I should do the tensioning procedure, but reach down with a bent hanger and pull on the tensioner harder than the spring normally pulls. Don't know if that hack actually works. But it could potentially add more tension without going back into the lower belt system.