Don't take this the wrong way but I don't understand the question? I'm not sure if you have a printer but it took about 2 min to set up, ~ 1.25 hours to print and it's done. I don't need to bother someone with a mill to spend their time working on my project. I don't need any additional weight, I like where all my weight is and this option worked great for me (although I wish it was a little longer, I'll probably print it again). Material wise it was less than .35 cents and with ~ 60% infill it's pretty durable. If you buy from Halcyon you end up with the same thing made of Delrin, if you get a mill to do it you get the same thing but it has some weight.
Multiple ways to skin a cat, it just depends on what works for you. The 3d printer worked for some of us and was a suggestion that I made. I think the milled way is beautiful and works for others. I think the idea is to gather multiple ideas / suggestions and use whatever works for YOU, the individual (lol). Hell if I didn't have a printer I might even try out a DIY PVC canister because I'm cheap, lol. Would also love to get a hold of a used canister just to keep keys in.
I guess I should disclose that I’m spoiled with the tools at my disposal as I own a small prototype shop with multiple fab techniques at my disposal.
I would not use a 3D printer for such simple geometry, my mill would be faster and the final product stronger with more materials to chose from.
That’s just my $.02, take it for what it’s worth.