I emailed ETS about this and got this response:
We don't currently have CZ P-10 C mags in the plan, but we are going to continue developing our line of translucent magazines so it may happen at some point in the future. We always announce new products on our Facebook and Instagram pages, as well as send emails to customers who have registered on our website to receive emails. Thank you for your inquiry.
So, no current plans, but it might happen later. Here's hoping!
I wouldn't personally use them for anything serious, but I'd love to use them for any normal range time I had. At their prices, I'd buy the crap out of them.