In some Embedded areas where safety is of high concern following the Motor Industry Software Reliability Association (MISRA) guidelines is a requirement.

There may be no heap at all and memory must be pre-allocated at system initialization. Otherwise CXXStateTree sounds like it could be very useful in my Embedded devices, which rarely have enough Flash or RAM space, which is the nature of the work.

https://misra.org.uk

I think it is possible to create a version with 0 heap allocation, try to open an issue with this feature request, we can see how to that togheter