You can try fairy max
How to define custom pieces in a fairy engine?

I tried fairy max. I found that the configuration file is impossible to decipher. This is a segment from the fairy max configuration file:
Rook:
R:500 1,3 16,3 -1,3 -16,3
Bishop:
15,3 17,3 -15,3 -17,3
I also looked at .ini files for fairy-stockfish and I find them to be undecipherable. Program language fail. The job of computer scientists is to design good programming languages, but they often fail. Computational physicists mock computer scientists for this reason.
I'm a computational physicist with a Caltech physics PhD and 24 papers in physics journals.
In the world of computational physics, you need a good engine, a good front end, and a good back end.
I succeeded because I did all 3. I wrote my own codes. I made front ends and back ends that my collaborators could use easily to drive the codes. The front end generates initial conditions and the back end analyzes the output.
I've tried many fairy engines and I find that they have weak front and back ends. I feel that the world of fairy chess needs to raise its game and provide good front and back ends that are easy to use.
I welcome collaboration with fairy chess researchers. This is the cutting edge of AI. Please message me.
Is there a fairy engine that can be run from the command line?
For example,
prompt: program.e < inputfile.txt > outputfile.txt
or, have the program automatically read from input.txt and output to output.txt
I ran fairy-stockfish, which gives you a command line, but I can't find a command to define a custom piece.
At the online stockfish fairy engine, you can load an .ini file but the utility doesn't acknowledge it. How to get it to acknowledge and use the pieces in the .ini file?
Is anyone researching fairy chess? I defined a computational physics research program at https://jaymaron.com/fairychess.html