Hey @brandon.haberkost, i’ve gotten some infos directly from Polyend on this.
The caps are a custom design created by Polyend that they keep to themselfs for now.
So you won’t find generic caps for it.
If you ever need replacement caps, feel free to contact customer support directly and they will gladly help ya.
On the more experimental side: i’ve so far seen one person actually replacing the keyswitches for their Play with cherry switches so that they could have more options for keycaps. I guess reverse engineering the caps for 3d printing would be an option as well.