Often I add to a playlist while video is playing by looking at the files in their own window and by right clicking then choosing Enqueue in SMPlayer. Worked great for me.
Now with the new update after I choose Enqueue in SMPlayer the files are added but SMPlayer is automatically brought to the foreground. Meaning I have to bring back the window with the files in it again. This wasn't how it used to react, I could quickly go through and choose which files I wanted to add but now it's a back and forth.
It's nothing major, just a little quirk that may take getting used to unless there is a little fix or setting I am not aware of to adjust?