While it’s been a while since I’ve worked with Flat Files… I can’t think of an easy way to accomplish what you want. The Delimiters are baked into the Schema definition.
You could have done some something custom inside a pipeline. Either a simple find and replace or some think more programmatic.
I’d probably have gone the route of 6 schemas as well. It’s straight forward. Only downside is if you need to make a change… I also think this fits the pattern a little better: one port, one schema, one format. Easy to add a 7th or turn off the 3rd.
Hope this helps.