Uncle, it's creme de la creme in self-absorption and those born post-90s.
Now we know what both of us are talking about.
If they come in at a fairly developed stage, this self-absorption might take some time to eradicate. Do they join you for lunch for example or a sports or group outing? We are all strangers to the unknown. Maybe give them some time. Keep on engaging them. Take them out from their enclaves. But I don't think what the Govt is doing is the right way. Spend a lot of money with doubtful results.
If they arrive young, say, from Primary school, good chance that they start from a clean slate and develop along the line of local children. They will develop the same accent of the Singaporean and even Singlish and unless they are very reserved, you may not find it easy to differentiate them from ordinary Singaporeans. Their Mandarin, particularly from the North, might be a give away but then they can also try to speak more 白。
For this age group, I think, the not overly rich are likely to set roots and integrate, pulling along their parents (in many cases, single parents, just their mothers). For the extremely rich, it is not easy to displace their distinct family culture and will move when their businesses move elsewhere. Or they may just follow where their Unis lead them.
I understand you have a strong stand on Taiwanese vs PRCs. But if we are talking about Chinese immigrants, the source I am truly comfortable with is Malaysia. They are culturally very similar to us, admittedly somewhat mercenary.
As for Taiwanese (you were not a Taiwanese?), I wouldn't be comfortable with the 李敖 type, very narrow in their perspective, measured on a localised set of values and understanding, suitable only for their local audience and I find many to be like that. Imagine laughing at Singaporean English. What a laugh?
So here we are. On one hand, the behaviour of the new rich (not all of them are rich). Those who travel far on their own money are. On the other hand, a bunch of country bumpkins who think they are better than you.