They are just crypto friendly but they are not even close to El Salvador if the subject here is how the country adapting Bitcoin technology. El Salvador definitely fully embraced Bitcoin to the point that there leader invest there country money on it. I think Singapore is just for Bitcoin acceptance same with Vietnam on adapting the use of Bitcoin in there economy.
Yes, in order for Singapore to follow in the same footsteps as El Salvador's, they need to declare bitcoin as a legal tender. I think they will never do so, not at least in the short/midterm and they will only support bitcoin acceptance only verbally. Anyways Singapore is much better than countries as they do not declare it illegal as many other neighboring countries.