GMT 400 finishing tips?

Any body got tips to do these right? Are yall putting foam on the top line? The encapsulation is never perfect, but can also be really wobbly on the top. Is there any way to even that out? Can I trim or shave the encapsulation without just making it look worse and doing tedious work for nothing? Can I get after it with a dremel and a heat gun? Is it just a conversation with the vehicle owner and shadow box situation? Its a pretty straight forward job, but the finish is always subpar because of that stupid wobbly encapsulation!