I added floating-point support to esp32-manager. I did not include it earlier because ESP-IDF does not support floating-point values to write in flash using NVS. What I do is converting the value in a goup of bytes of no particular type (void) and write it on flash as a generic binary.
You can use it in your program like any other type of setting.
Check it out: https://github.com/pablobacho/esp32-manager