Several ideas to modify the autonomy floor.
Two ideas:
1) To solve the move capital to North America problem: Increase Local Autonomy of all provinces in proportion to the distance the capital has moved. Eg. Moving 1 province wouldn't cause much of an administrative problem, but moving across an ocean might.
2) Have minimum autonomy tied to the amount of time an adjacent primary culture core has been a core. Eg. Colonise a province that has no adjacent primary culture core and the minimum autonomy would be, lets say, 50%. Colonise a province which is next to a primary culture core that has been so for 25 years and the minimum autonomy is 25%. Colonise a province that is adjacent to a primary culture core that has been so for 50 years and the minimum autonomy is 0%.
Just my two cents,
Harvey.
1. Make a modifier, "-X% Minimum Colonial Autonomy" that can decrease the 50% malus based on the total of these modifiers you have.
2. Give certain nations / groups Ideas, Traditions, and/or Ambitions that include this modifier at varying levels. So Russian states might get a -20% Minimum Colonial Autonomy as an Ambition, for example, so that by late game their colonies are producing more.
3. Put smaller modifiers late into an Idea Group (say, the finisher for Expansion as -10%) and a Policy (at -15%). Nations that have the modifier built in can stack with the idea group and the policy to nearly or fully remove the penalty by the time they're able to accumulate all the requirements (late game). Nations without the modifier should still be able to get to around 25% Autonomy by stacking the idea and the policy.
I'm coming to this thread a little late and I haven't read all 175+ posts so I may have missed something but it seems to me that the purpose behind this mechanic is to recognise the absurdity that nations colonising on their home continent could grow rapidly without any obvious source of population to properly support the power that the game would give them if all of these newly colonised provinces were giving 100% of their manpower, tax and trade.
There is nothing inherently wrong with recognising the absurdity of that premise and it applies to natives just as much as it does to Europeans because, in both cases, they simply do not have the population to support such rapid growth in economic power.
Taking all of that into account, it seems to me that the best way to address this issue is to have a tapering modifier (probably using the new autonomy mechanics) which applies to every colonised province but to have a second modifier which affects the rate at which the first modifier tapers. The first modifier would essentially represent the time needed to grow from a newly established town of 1,000 people to a fully functioning province. I'm not going to suggest a value because I haven't used the autonomy mechanics but, whatever the value is, I suggest it should be more of a handicap the further away from the capital to reflect a reduced growth rate in such circumstances.
Whilst this may appear to mean that Russia, for example, is not nerfed by this, the modified taper is my proposed solution. This taper would affect the rate at which the first modifier wears off. If you have one former colony then the taper rate could be relatively quick (again reduced for distance) but as you increase the number of colonies that have not yet developed into provinces the taper would get exponentially slower to reflect the impossibility of growing hundreds of colonies from the same core population.
Applying mechanics like this (which would clearly need to be in a major patch rather than a hotfix or a minor update) would also allow for this growth rate taper to take into account the size of the colonising nation (because bigger nations should get an advantage) as well as add new religious bonuses such as Catholics and Muslims having a faster growth rate because of historically larger families than Protestant or Reformed.
It would also mean that the natives who expand would lose the autonomy in that neighbouring province over time whilst Spain or Russia would find that their colonial efforts gave them territory but little other benefits (unless they find gold).
Does this address all of the issues in a practical way or have I missed something because I didn't read every post? I'm NOT asking if people agree with the concept of nerfing the home continent colonisers because that is the decision that Paradox has taken and so debating whether or not it is right simply distracts from helping them find a better way to achieve that objective.