About C-Gear RNG...
In Dragon Quest IX, we manipulate non-groto chest by opening a map and entering a room to fix a seed. Once the seed is fixed, the item-per-frame list is always the same and all that is left to do is advance the appropriate number of frames for the desired item and them open the chest.
For In-Groto chests the seed is fixed when you enter the grotto, the item-per-frame list is also always the same for that seed and it advances one frame per second while we are viewing the battle records. One the desired item is on the top of the timer list, we exit the battle records screen and open the chest.
Here's a chest timer to illustrate this.
I'm assuming the PID-Nature-Ability for BW is similar as the In-Grotto's chest items. So is there no way to calculate the nature-per-frame list for a given seed+mac so we can just let the C-Gear run and turn it off on the desired nature?