$NIO Inc.(NIO)$I'm not sure if secondary listing is the right term since this is technical the 3rd one. Hence, tertiary listing perhaps?

If NIO's aim is to raise funding from the Singapore government or to obtain grants and tax incentives, that would be a great idea. 

Otherwise, I would think listing in $SINGAPORE EXCHANGE LIMITED(S68.SI)$isn't a good idea. It has a very small market cap, the performance are flaccid at best and suspiciously manipulated by greater powers at play. It's common to see 'sell on news' for good counters, showing the lack of faith in the stocks. 

Coupled with the expensive regulatory requirement for board listing, is it really worth it?You don't see $Tesla Motors(TSLA)$ listing in Singapore despite the grants and incentives from the local government, just to reinforce my point above. 

I think the Thailand stock exchange is more vibrant and suitable for a company like NIO. The environment is more exciting, and it is still a manufacturing country which makes sense for NIO to list and even produce there.