Once you have the appropriate disguise and charisma, you should be able to access lower descriptors of your appearance using the appear command. i.e. appear ugly/plain/good-looking/etc.
|-||itsrikka||24s||Runner. Whatcha need?|
|-||Bruhlicious||5s||Deine Mutter stinkt nach Erbrochenem und Bier.|
|j||Johnny||1d||New Code Written Nightly. Not a GM.|
|And 13 more hiding and/or disguised|
I think this is acceptable, but if you can pretend to be ugly you should also (with enough skill) be able to beautify yourself to pretend to be more attractive (real life make-up already works like this).
Also I don't think this would work along with disguise items that hide your facial features for obvious reasons.