I did...
Simple attributes to ignore files (any file).
A simple setting to ignore file.
It doesn't I believe (maybe you have fixed this and I haven't found the right docs, ok cool my bad) (see below)
No matter how complicated what you are trying to do is, simply adding something like type="parcel/ignore" isn't really rocket science. I am sure there are many other just as satisfactory ways.
I have been using Parcel today as an experiment on real code (as to other options). As I'm testing it it is just a local file system and a simple game (just used for testing stuff). Firstly some issues with local image resources that were fixed with "require" which was in itself not very good but that's a different issue. Mostly it just doesn't work when trying to include other JavaScript files that you want Parcel to ignore (and there are many good reasons for doing this). After Googling this a lot this evening I see bodges and add on's etc. etc. (and many folk complaining about such). But lets be honest this is an easy fix. Simply read an attribute that says hey Parcel just ignore me. That really isn't hard to add. I find it bizarre that library's such as this can do loads of complicated stuff and yet seem to ignore really easy fixes that are needed in the real world.
Just add something like type="parcel/ignore" or whatever to the tags.