This was already resolved. The Proclomation line was a pro-settler policy, to make sure the South East was settled by British colonists. This would have prevented any encroachment from Spainish or French Colonists.
British colonists were to egalitarian for nobility to work. Which is why it failed in the American, Australasian and African colonies. As for whether it colonial upper classes wanted that status, idk?
All they wanted was autonomy, which they had prior to post-7yw. So a giant conglomerated state isn't essential.
No French funding, no Napoleon, no Spanish rebellions.