This is a function that would let users customize the function of the middle click/scroll wheel. As it currently is, middle click is used for element sampling, which is also accomplished by alt-click. 

Possible functions:

• Element Sampling (no change)
• Delete (more accessible than ctrl-;, more convenient than keeping secondary element as delete)
• Tertiary Element ( :o )
• View Cycler (Not that interesting, but maybe for some people it's useful)

There are probably many other that I didn't think of.

Preferably, these would be uses that are already in the game (because of laptop users/people without middle click).

This is pretty much a usability feature, and hopefully a good/feasible idea.

@boxmein (View Post)

 I just tested it, and it does seem to show in a blue outline. However, I have no idea how to use it from there, contrary to what this would provide (also, it's not a widely known command at all, unlike something in the preferences menu).

Besides, there are other options besides the tertiary element.