Can the same subdomain be used on different domains and can this be prevented?

Hi, I am not sure what the plugin can (not) do, hence my question:

The situation:

– I have a working subdomain network setup.

– However the domain name is spelled differently in US vs the rest of the world (think colour vs color etc).

– So currently sub.color.com works, but sub.colour.com does not

– I own both colour.com as well as color.com

Questions:

(1): If I use the MultiDomains plugin, can the same subdomain be registered on both (or more) domains?

So user1.color.com and user1.colour.com can both be registered, or does registration for one domain exclude the same sub for all other domains?

(2) If so, is there a way to stop/limit this as it would be confusing to have 2 the same subs on similar domains.

(3) Is there a way, using this plugin or alias or whatever to have all subs.color.com also work on subs.colour.com and vice versa. Preferable without redirecting (so somebody that types sub1.color.com should stay on it and not get redirected to sub1.colour.com or worse, the sign-up page on colour.com)

Basically I don’t want people to worry about different ways of writing the domain including prevention of registration of the same subdomain.

Cheers