I think drilling a 1/16" hole is a good thing. If anything it helps the system bleed faster. I've been doing this for years. I think others do it too, some drill more than one hole.

Becareful though, too many holes you're heater won't work worth a damn because your motor won't go up to temperature. I personally found that x2 1/16" holes were too much, just by going with one was just right and I still had a heater here in Oklahoma.....