Rationalists should win. If your goals are better fulfilled by not playing with the herd, then don't play with the herd. If your goal are better fulfilled by playing with the herd, then play with the herd.

With regards to signalling, the problem is that people can't read your thoughts. The see that you do X, but they don't know why you do X. They can often make a wrong hypothesis. It's not like when you do X, there is a bubble above your head saying "I am doing X because of Y". For example you may refuse to participate in some group activity for ethical or philosophical reasons, but others may think you simply lack the required skills. So there is a risk that these signals will be weaker or different than you imagine.

Also, being a "slave to the opinions of the herd" has unnecessarily bad connotations. To balance this, the word "minister" originally meant "servant"; and the Catholic Pops calls himself "Servant of the servants of God". So, some kinds of servitude are actually positions of great power. If for some instrumental purposes you want to lead the herd, you must understand the herd and avoid violating their assumptions, because if you act too strangely, the herd will not follow. There is an NLP technique called "pacing and leading", which means you start by following and then gradually switch to leading, and if you succeed to not break the mood, people will follow to preserve the perceived status quo.

I am not trying to convince you to do things you find revolting. If you really find them revolting, you would probably do them wrong even if you tried. Just saying that from a different point of view, they don't have to be revolting.