...However, I think you missed the purpose of my original post. This was for TESTING PURPOSES only using a subdomain on a different server
Assuming that this is in relation to the TTL adjustment, and assuming that I did miss the purpose, I now feel obligated to state that reducing the TTL is probably even more important than I previously implied. When the testing has ended, and assuming that there is no longer a need for the test subdomain to exist, the short TTL can wipe it from existence in just a few minutes. The long TTL will create a zombie site... In reality it will be "dead", but the DNS records will make it appear to be still alive for several (12) hours.

Just sayin' ;-)