Tandem Cycling - timing chain

the tension on our timing chain is not consistent - I read Sheldon Brown's article on this (you need to loosen chainring bolts and tap on the chain until chainring is centered) but haven't been successful with this tedious process. As long as the tension is never too great is it really an issue?

Not an issue.
Rotate pedals backwards and watch timing chain. At some point it will be tighter/looser than in others.
Too tight and chain can snap; too loose and it can bounce off. Settle for the happy medium.

.... As long as the tension is never too great is it really an issue?

The only potential problem you can run into with sync chain tension is having it too loose, which could lead to an unintentional derail / drop of the chain at an inopportune time.

As far as getting it too tight, you would have to use a breaker bar on the eccentric to put the chain under anything that comes even close to the amount tension that your average captain generates through the pedals on a normal ride, never mind on strenuous double-digit climbs.

Bottom Line: Close enough is good enough as long as there isn't too much slack.

+1, as a mechanic, one learns chains are not "round", they always have tight and loose
R&J

the tension on our timing chain is not consistent - I read Sheldon Brown's article on this (you need to loosen chainring bolts and tap on the chain until chainring is centered) but haven't been successful with this tedious process. As long as the tension is never too great is it really an issue?

I was able to get to a higher level of 'close enough' by using that technique.

On my Santana with Shimano Ultegra crankset there is noticeable tightening / loosening while rotating the cranks. I was suprised on the Calfee with FSA crankset / rings there is no detectable tightening / loosening. I am not sure if it is a function of the frame, crankset, rings or all three but it is noticeably improved on the Calfee.

thanks everyone!

On my Santana with Shimano Ultegra crankset there is noticeable tightening / loosening while rotating the cranks. I was suprised on the Calfee with FSA crankset / rings there is no detectable tightening / loosening. I am not sure if it is a function of the frame, crankset, rings or all three but it is noticeably improved on the Calfee.
I noted the same thing with my Calfee / FSA compared to my Santana Rio with Shimano / Ultegra.