Even with the highest migration setting of 20% migration there is no evidence that this is working. I'd expect to see similar indicator price level combos appearing in one island up till the specified migration period and then I'd expect other islands to start to produce some same/similar patterns from other islands. But that doesn't happen at all, or at least it happens so rarely and ambiguously (only partial matches) that it could be explained by chance. The similar indicator/price level combo's remain isolated each to their own island 99.99% of the time even at 20% migration rate. 20% should produce a noticeable effect. I tried waiting to see if migration would happen on a new reset but nothing from last reset appears in the future islands either.
In the screenshots I have highlighted each islands strategies one at a time. You can see which island it came from in the strategy name, the first number in the sequence represents this. It was set to migrate 14th generation 20%.I have done this several times, this is a typical result.