The design looks solid. I do have some suggestions.
1st; unless you’re buying the sheets at 12x20 you won’t be able to cut that in the 
- the max cutting area is ~11.5x19.5 (it varies slightly by machine)
Kerf varies for every machine/piece of material so I’d definitely cut one set and make sure you have the right dimensions and enough counter-acting force to keep them standing. It looks like you do, but without testing…
Acrylic tends to split at hard corners. There is a tutorial on here about adding tiny curves to all your corners. First thing you’d have to change your items from objects to paths, and then modify the corners. This thread has links to instructions for different programs.
Stay safe!