Can you choose coordinates for the decal placement?

So I am trying to place the decals in custom locations -- would like to just have a (row,col) coordinate for placing the decals.

I can see right now how I change the decal frequency and control how many I will have (some decimal that is diving into 100) -- but then they are randomly placed. I see that once it randomly places them it keeps that configuration for the maze, no matter how many times I run the maze -- but still doesn't let me place them where I want. So how can I chose where they get placed? Thanks so much !!

Here is where I can see I can edit the decal frequency:
/lab/game_scripts/themes
in file themes.lua

this line:
local decalFrequency = opts.decalFrequency or 0.01

0.01 makes 1 decal, 0.1 makes 10 decals... etc