Mos.exe secure alternative

I am setting up an IoT test environment. Part of the setup is the installation of Mongoose OS to an IoT-device. The procedure includes the download and execution of an unsigned mos.exe file. This is something I wouldn’t even consider to do on my private gaming PC much less in a corporate environment. Does anyone has experience with Mongoose OS and knows a save way of using it.

Here a few more details. I am using an ESP32 or ESP8266, which will hold certificates to talk over my wifi to AWS.