I am interested in procuring your whois WP plugin. I checked your demo to see if the WHOIS input supports IDN. It seems to accept IDN inputs such as Chinese "中文". However, it doesn't seem to know that the domain is registered. For example:
中文.asia is reported by the plugin as AVAILABLE, but when I go to .asia (www.whois.asia), the domain is UNAVAILABLE (and showing registration data).
Can you let me know if IDN is in fact supported?