When saving the model as XML (.fsx), the numerical values of tree nodes are saved in binary (hexadecimal) format. This is a reasonable serialization choice to load exactly the same numerical values later, but these dumps are not human-readable and are opaque for external tooling.
In particular, they defeat the idea of using the XML format for version control, because diffs cannot be easily interpreted. We can see what nodes were changed, but not how:
I suggest to add an additional attribute for data nodes, which will contain a human-readable representation of the value. Something along the lines of:
<node f="42" dt="1"> <name>itemcurrent</name> <data value="0.0">0000000000000000</data> </node>
The additional attribute can be ignored when loading the file.
