actually it would be better to wait until the next release so that you can specify the Height and Width of the logo in the 'Edit Board Images' which is where that one part of the Easy Customization will move to-so that if the Easy Customization is disabled you can specify the logo in that Edit Board Images
In the Easy Customization currently it is not possible to specify a Height and Width for the logo so once that has changed in a couple weeks when the next release is out you can go to that Edit Board Images
screen and enter in the height of 245 and that width of 406.
So if you don't mind waiting-when you see the next version BbV1.3.8 go live you can go to that screen and after the URL that will be in there (All current logo URL's will be moved with the option into the Edit Board Images Screen) you can add those Heigth and Wdith tags on the end like BbAdminMod posted here.
Thanks for the compliment on the system. We work very hard to improve things and make them as simple to use and intuitive as possible.