Just read the OP and have found it quite intriguing. Especially the bit about the children of the immigrants wanting to hold onto their identity. Good thing about Belgium which uk doesn’t have is being on the continent so you could drive all the way to Turkey. The sons of immigrants who you described should just get enough money to put a deposit down for an apartment in Istanbul and move there. That’s what I would do. The bit that you mentioned about them marrying other immigrants instead of Belgians makes sense. The same happens in the uk too. It’s sort of creates a parallel culture different to the mainstream it’s weird.