First of all congratulations for liquibase implementation in Sqlcl, this is one of the most amazing things I've seen previous years from Oracle.
I've been playing with it a bit, and is amazing but I faced some issues that I lost hours fixing by myself and it would be a nive thing to have as standard if 90% use cases is like that:
1 - genSchema should support apex and ords types right away without needing to use genObject.
2- genSchema should support object_type, in order to filter just by object type. It would also be nice having a from_date to only have changes from given date.
3 - In windows JAVA_TOOL_OPTIONS environment variable must be set to -Dfile.encoding=UTF-8 in order to liquibase's sqlcl implementation to work. This should by by default.
4 - genSchema multi schema support. This could be achieved in two ways, one is just using a user with access to a given schema list (ex SYS, SYSTEM or whatever). And the other one would be with a Oracle wallet connection stored credentials. With the Oracle wallet variant you woudn't even need specifying user or password, just wallet credential list. The same for update, multi schema support. Mos of the times all goes ok if you first create all tables in all schemas, and then you apply the rest of changes and compile invalids at end.