I am using nidacore th core my decks.. I know of a few custom builders who used nida core for there 36 - 70 footers.. And here is ther solution where hardware mounts recore with structural foam or teak imbeded in epoxy then embed ..
1/4 to 3/8 inch ss or aluminum . Plate once cured position tower and drill and tap or drill thru and bolt.. Depending on clearance.. At least that iwhat i amgoing to do.. As for the foam or teak i am going to router out the top lyer of glass an expose the comb then pour there ceramic transome corebond then glass over ... And still use alum or ss back plates...and 5200