I am wondering how is with internationalized domain names. For example सदस्य.com is Chinese domain name.
But the problem is that I see in Firefox address bar सदस्य.com and not सदस्य.com. The content of the page is shown properly with chinese characters. Also if I type www.something.com/सदस्य is shown properly.
Will all users see in their browser सदस्य.com? Or is any way that Chinese users will see in browser सदस्य and not xn–j2bszb9h?
Will all users see in their browser सदस्य.com? Or is any way that Chinese users will see in browser सदस्य and not xn–j2bszb9h?
Mostly depend on the browser settings each user has
Most users will see the XN- version, the reason for this is because early on (during the testing stage) it was noted that people would use Unicode characters that look like alphabet values to try and “spoof” people into thinking they are on another website. For example using a couple of “look-alike” characters in lingual alphabets you could make a domain which looks like it says “paypal.com” which is pretty dangerous. As it would increase the potential for fraud and phishing, all IDN’s are “translated” to the XN convention (for the benefit of site visitors), and browsers follow this convention of such representation 
I think you need to understand purpose of such domain name usage. If they are the ones for the Chinese visitors only - why not? If they are worldwide you need to do everything to have such domain name displayed properly
What makes you think he doesn’t know what he’s doing? From what he posted it seemed like the only people he wanted to see the site would be proficient in Chinese.