My colleague and I conducting a research proposal about using natural materials such as mahogany, bamboo and coconut tree as modules in coral transplantation of Pocillopora verrucosa.
My experience with coral recruitment and settlement in the past is that biodegradable substrates, like wood, are not really suitable for coral planulae settlement. The physical nature of wood or bamboo, as well as possible release of various chemical from the decomposing wood are an issue that you should consider. My suggestion would be to use old carbonate rock or even mad made inexpensive materials like terracotta tiles. I attach a few papers that may help.
the term invasive coral species is a bit vague,,,wt regards to the biodegradable materials like bamboo, these could be threats to the reef itself when displaced during bad weather,,,,
I concur with the previous respondents that wood is not a good transplant medium. Limestone or terracotta would be a better substrate.
The possibility of non-native species invading your transplanting area is marginal in that larvae or other forms of propagules are not likely to settle on your substrates. Should such a thing to occur, you should physically remove the non-native from your areas.