I tried that. I changed the Height parameter from 50 to 200 but it didn't appear to change the width of the font underline?
From: ***@lab6.com
Date: Fri, 20 Mar 2015 08:30:15 -0400
To: fontforge-***@lists.sourceforge.net
Subject: Re: [fontforge-users] How do you increase the width of underline
Element, Font Info, General, Height