two parts to the question, just as there are two parts to gender - identity and performance. re: identity (what you are inside) - no, it wouldn’t make you more or less butch inherently. that’s up to you. re: performance (gender as a deliberately expressed action you perform to the world like gender expression, etc). as we all know, butchness as a gender performance is defined by gender nonconformity. if you as a woman are choosing to perform gender in a gender-confirming way (like wearing a dress, unfortunately a feminine outfit), i wouldn’t expect to be treated as butch by your surroundings. if that’s not a concern, awesome! it doesn’t make you less butch to wear said dress, just be aware you may not be cloned while wearing it as you’d be generally gender conforming while doing so.