To be honest, skim coat is not an issue. Workmanship is the key.

I paid my contractor to do inside my house. After switching on my lights after dark, I was glad that I did not waste my money to do the external wall.

Some video clips show how the contractors in China do it nicely. But, honestly, few contractors in Malaysia have those equipment and I doubt their foreign workers could deliver the same effects.

I did explore various options available to do smooth external walls. Installing facade cladding probably is better. But, this is costly.

Stormer.lyn gave you the right URL search.

There are various types of materials to choose, Aluminum Composite Panel (ACP), Prefinished Fiber Cement Cladding, and etc

https://www.arch2o.com/how-to-choose-from-t...ding-materials/

You don't have to paint, many design patterns, smooth and nice design. Most of the shopping centres are using this.

As for external skim coat, if your house is 2-storey and above, I don't think you will like the effects after paying the RM 4 - 6 psf for the work. Local renovation contractors just do not have the skills and workmanship. They just collect money from you and outsource to those foreign labour to carry out the work.