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.
Eh, I just really like SMW. I don't make hacks (too lazy), but I do like putting together other peoples hacks to make a new version of SMW. I also really like Yoshi's Island, but nobody makes hacks for it