Yes, I've heard that tasteful wealth signaling implies that you're successful enough to do so, and if you're a bit over the top, you likely need the job more than someone who is a bit more reserved, so you may work harder.

Basically, fake the til you make it and dress for the part and whatnot.

However, each position and manager are different, so there are very few hard and fast rules. What works great for one person may have the opposite effect on another. Honestly, I don't care too much about my physical appearance (I guess that's signaling too), so I've been looking into other nonverbal ways to communicate since I hate trying to adapt to the latest fashion (it's exhausting, and my time is better spent building stuff).