Tip: If you place a moon, midpoint, or dragon coin through Map16, it will always respawn whenever you reenter that sublevel. It will not respawn if you add it through the Add Objects/Extended Objects window.
Having a bit of trouble getting everything working properly. (Using SA-1 Rom) I've inserted the blocks using GPS and used UberAsmTool to import the code provided, but for whatever reason the switches aren't solid and Mario cannot interact with them, and the blocks are just acting odd in general. Did I miss an important step somewhere? But besides all that, (from the GIF at least) great work! It looks awesome.