Ever since they came out with reasonably priced lasers 10 years ago or so, I’ve been using a laser to set the first row and never went back to a ledger board. Always found it to take more time and effort to piece in later, plus as you mentioned there is a waterproofing issue that will need fixed
I have not found a situation yet, where I’ve gone back to the ledger board….
I guess maybe if I was held up by a tile order and did not have the shower floor tile, I’d consider going back to the ledger method
