I'm getting ready to build a single tree platform in a 16 year old Live Oak which has a 21" diameter. About 2 months ago I removed a lower branch that had a 5" diameter at the collar. It just so happens that is where I would like to install a Tree Tab for one of my support beams. The other side of the trunk has no issues where the other Tab is going. If I lower the Tab's the Beams will be a hazzard. I can't go higher because the Trunk splits at that point and I will loose Headroom. My questions are ; Is it OK to drill into the collar or old branch to install the Tab? Will the tree heal or will it cause rot?