First, to handle your simple example, you could create a table that had "MyValue" and "MyOutput" as columns and simply use a lookup component. Not only would this be easier than either of your solutions, but it would allow you to handle additional cases without changing your package.

Now, assuming you have a far more complicated CASE, another option would be to use a conditional split. Handle the case in the conditionals and use a simple derived column on each output to add the "MyOutput" and then finally use a UNION ALL to put it all back together. Although this is a lot more components, it is not going to add a lot of overhead and will be really easy to follow in the data flow.

Now, the unfortunate reality for your situation is that ETL developers using SSIS will eventually need to dive into .Net at least at a basic level. The script component is too important to simply try to avoid all of the time. Anyone complaining that it is too hard to learn needs to get a reality check. Part of a developer's job is to learn to use new technology. So, you may really want to use this as an opportunity to get your people on-board - bring in a .Net trainer for a basic 1-day class for everyone.