Hi 3image, yes it's possible to deactivate the RMB repeat for specific commands. To do this go to Options > General > "Edit .ini file" button, and inside moi.ini find the [Commands] section and there's a NonRepeatingCommands= entry in there which contains a list of command names which will not be repeated like that. By default it includes the delete, undo, and redo commands and you can add in whatever additional commands you want in there.

So for example set it to:

[Commands]
NonRepeatingCommands=delete undo redo copyclipboard paste

Hope that helps!

- Michael