I thought about getting this and trying this at some point, but as someone who has a bit of experience in rpgmaker I might be having second thoughts. I watched this video:
https://www.youtube.com/watch?v=TKSuzRR3cQ4
To give me a better idea of the capabilities, and it seems that the FES is pretty much a portable version of VX Ace. There were a few things the review I linked mentioned which could prove troublesome to those wanting to make a spanking game in it. One is how there seems to be a set limit on the amount of different items, armors, and weapons you can have in a game. From what I remember, there wasn't such a limit to VX Ace. A good thing I found out, is that there are 500 possible switches you can use for events, and even if that runs out I expect there are similar amount of variables to do the same thing. There is no sprite customization aside from colors, and I imagine that the sounds work a similar way where you can change the pitch and volume like in VX. So if there isn't a good sound for slapping, there won't be much of a point for anyone here. With how the game is on a handheld system, this changes two things I noticed specifically. Firstly, making maps and changing values in the menus should be a good bit easier with the stylus being faster and more precise than a mouse (on average). However, writing text and dialogue on the tiny 3DS screen (even an XL is pretty small) would be a real pain in the ass. As all spanking games are pretty heavy on the dialogue, I don't imagine this being a fun change. Lastly, after poking around on Gamefaqs for some other opinions, it appears there is a built in language filter into the game, and it can be pretty strict in what it blocks out. No clue if this is fixed, but either way you're looking at a pretty PG game, even if you weren't planning on uploading it to anything. Speaking of, that is the last concern. If there is no other way to get a game out there than uploading it to public servers, then you can kiss the thought of anyone else here playing your game goodbye.
But don't let my thoughts dissuade anyone. If they think they can get away with making a game with spankings in it and somehow upload it too, good luck.