what was that website i can go to to define a custom shaped LED matrix? i think @Garrett_Mace was the one who shared it.
That’s it, but oh wow that would be tough to use for a snowflake shape 
It’s better for weird shapes that you have filled with horizontal strips plus some gaps and cutouts. Snowflake is sparse but regular, you can just do it with math
If all the snowflake arms are wired the same way you’ll still easily be able to do some great patterns.
Unless you’re wanting to do some specific patterns, or a color gradient or pattern moving across the whole snowflake you shouldn’t need to XY map to still make some great visuals. And after playing around with it you can always add the XY mapping later if you want to go further.
I really juat want to experiment with it and see how it looks
Then you should certainly go for it!
In the case of your layout though you’re going to need to do a fair amount of hand editing of the XYTable.
Yeah i did the same thing last year but since my laptop was wiped completely i have no record of it. In any case i had no idea what i was doing last year anyways lol