When using aliases, you also have to make sure that your code does the proper translations between the aliases used for notation and the piece labels used for displaying the pieces. Since the code in betza.txt does not contain the keywords alias or realname, I expect it is working with the assumption that there are no aliases. The tutorial for the fairychess include file explains how aliases may be used, which may be of help to H. G. if he chooses to add support for them. In the meantime, you would probably break your generated preset if you tried to use aliases with it.
When using aliases, you also have to make sure that your code does the proper translations between the aliases used for notation and the piece labels used for displaying the pieces. Since the code in betza.txt does not contain the keywords alias or realname, I expect it is working with the assumption that there are no aliases. The tutorial for the fairychess include file explains how aliases may be used, which may be of help to H. G. if he chooses to add support for them. In the meantime, you would
probablybreak your generated preset if you tried to use aliases with it.