I had a 1/4" multiply drum shell that I was going to try a few years ago.. I was worried that the shoe brackets and the head of the bolts would squash the multi ply shell and meet in the middle.. Maybe yours is better quality
It depends on what the plies are made of... "a chain is only as strong as its weakest link".
Many banjo makers (some very well known...) use slices of Keller (or other) drum shells with no problems. I've used them many times myself. Standard Keller shells are 10-7/8" outer diameter and are about 1/4" thick. They are made from thin layers of maple or other hardwood and have either 7 or 9 layers, I don't remember which at the moment and warm coffee is preventing me from venturing outside to the shop to check. When I use them I add a full 1/16" layer of a more attractive wood veneer to the outside, bringing them to 11" O.D.
My point is that a 1/4" thick rim will work fine if it's made of hardwood and well constructed.
I have used numerous products from them, including their veneer, and have never been disappointed. Maybe it goes against your quick and dirty plan but you might consider it in the future. Making banjos is like eating Lay's potato chips. You can't build just one.
Zach Hoyt, builder and frequent contributor to this site just used a Keller drum shell for a banjo. It is listed in the Marketplace right now for sale. It is a very nice looking banjo. He could give some insight if you contact him.