Reddit user nalk1710 made a handy app that calculates optimal hyper berry use for legendary donuts in Legends: Z-A: This guide helps you figure out if it is possible to create each donut based on your inventory. It also suggests an economical (using fewer rare berries) and a luxurious (using rare berries, giving full power) recipe.
A friend of mine on Bluesky called deeb found some 3D models of Bowser’s Keep from the Switch version of Super Mario RPG and tried his hand at 3D printing it. If you want to skip to a more finished product, here it is.