Yes, we have. The downside of that design is that it increases the price of the device approximately twofold, which makes it impractical for many applications. We have designed a customized version of Myxa for one of our clients though which leverages ceramic caps at the cost of being considerably more expensive.
What you said about the downsides of electrolytic capacitors is true; however, I would like to point out that the capacitor used in Myxa is a high-reliability high-MTBF model United Chemi-Con EKZN800ELL391MK25S rated for -40+105 ºC, 10000 hours at +105 ºC. Myxa is designed for 3 years of service life with the projected MTBF of 70000-100000 hours, and this particular capacitor fits the service time requirement well.