Yes, what you're trying to do seems possible. But I'm still missing a lot of information from you about exactly what is going wrong.
Pattern Matching can't find empty results... it's job is to capture characters and if there aren't any characters, it won't capture anything. When there's a mixture of content and missing content (say, capturing a pattern across multiple lines where some lines are blank), it's still only going to return the content that is present and ignore everything else.
Zone OCR might work instead, if the content is always in the same place (note that you'd need to turn on some "Advanced options" to capture multiple lines as a multivalue token).
When PM doesn't capture any values, what do you want the token value to be? Blank? I'm actually not sure why it doesn't do this already, but you can work around it by using a Conditional process + Assign Token Value process. The Conditional checks if the multivalue token, with the Value Count function applied, equals zero. And, if so, the Assign Token Value process updates the value of the PM token to be blank (or whatever default you want).
Capture Profiles may also be helpful in this situation, but that's a whole different conversation.
As for the "token editor never works", I'm not aware of any issues/bugs with it, but you still haven't told me what you mean by "never seems to work". Without that information, I don't know how to help you. Maybe ask a colleague or your Solution Provider for some help with it?