I suspect the memory research that justifies spaced repetition might not apply to skill development as opposed to simple recognition and recall. This might simply require experimentation to settle? I dunno.

I think that the theory that 'procedural memory decay at the same rate as declarative memory' is a reasonable default theory, and I haven't noticed any real difference in average grade (accuracy of recall) for my programming cards and my more normal flashcards. But certainly I pay attention to any research I come across which seems like it might be germane.

Similar reasoning suggests that, it might be good to memorize the name and purpose of all the commonly tools that can be installed and run library in debian from the command line, and all the libraries that exist in one's preferred programming language.

The problem with that is that memorizing all random tools is a big commitment. There are hundreds and thousands of such tools, which will cost you many hours, and you will only ever look up or want a small fraction of them, and search is fast. How long does it take to refind a tool via Google or just apt-cache search? A few seconds?

If search is always less than 5 minutes, eg., there's little or no point in memorizing the list, because even if you eventually used every single entry in the list, you still have a net loss of time.