I read: tweens are in seconds (s) instead of milliseconds (ms) now.
After testing = changing a tween; it is now indeed in seconds.
Does that mean that I have to change, update manually every old ms-tween which is in my project?
Or is it ok to have both s-tweens and ms-tweens.
Hi! In my current project the tweens which I have created before the update are still in milliseconds, and they are working fine. However, if I create a new tween, it asks the time in seconds. So, it looks like that there is no need for changing anything. The “old tweens” and “new tweens” are working side by side.
This change might feel irritating, but I understand the developers. On the long run it’s wise to try to harmonize this kind of things, e.g. wait action, timer and tween use seconds from now on.
@PalelevaPingviini : Thank you for your detailed clarifying answer, that you are having the same experience with tweens.
Indeed, it seems like a wise and good decision, but I’m worrying about the performance on the final product. Do you recommend to update the old tweens to the new ones?
I don’t have any real data, but I believe that there won’t be any performance issues between the old and new tween. The new tween is just the “overload” function (in Java terms).
If you have new and old tweens in the same project, I guess that the biggest problem is to remember writing the time in correct form. In fact yesterday evening it took me a while to figure out, why the button didn’t fade in. Finally I found out that I had defined the opacity tween to be executed in 500 seconds when the purpose was to get the button visible in 500 milliseconds… 
Haha… same here, tearing my hair out, wondering why the Tween wasn’t working for a good hour … then DUH! I saw it was changed to seconds. LOL!!! Carry on… 