Random photo: One Does Not Simply Get a Tour of 21st Amendment Brewery
Recently I have shared code how to set up a custom profile for local Firefox and Chrome. Then I tried to do the same for remote Firefox and Chrome. As usual, I had no problems with Firefox, but Chrome was significantly harder.
After reading the documentation and source code, contacting Sauce Labs support, asking at watir-general, selenium-users and Stack Overflow, offering maximum bounty for the question (500 reputation) and poking Jari on Twitter, I got the answer. Jari, thanks again.