Hi, I'm still playing with the bubblewrap of SimplePress 4. And what I'm seeing so far I like – very much. Now, I'm not too much in the way of a skinner, but I like type (font) consistency – so I've done a straightforward mod of all font-family declarations in the CSS files to suit the rest of the site I'll probably put it “in production” on.
Of course, the problem with that is that an update / upgrade will wipe out those mods, so…
I'm wondering whether it's possible to include some way to accommodate preserved customization of the CSS – e.g. via an external but “safely” located file, or by some override mechanism (and embedding the custom bits in the “standard” WP theme folder CSS file, or via a database blob, or…
Dunno. I guess I'll copy my CSS files in the meantime, just in case! 
(Um, if I overlooked something already in place for that… Please delete this post and shoot me, in whichever most convenient order)

