Not sure but I have used the Marco cement in the past and it works great. I made small batches at a time and would build a section and just kept on doing it that way because it actually sets very quickly. So if worst comes to worst you can experiment with it on your own. I met a guy that would build crazy rock structures and he actually sold some at rap last year but I can’t for the life of me remember the name of his company if u can find the vendor list from rap tx 2023 id imagine that he would be listed. All of his structures had frag plug sized holes all throughout so corals can easily be placed and removed if need be. Ik top shelf sells structures but I’m not sure if they would be willing to ship them out.