Retired with too much time on my hands… I wondered why Sketchup did not have a dedicated COPY command… so of course I thought as a good forum user I would do a post search first 
You know! Just like the MOVE command… considering it is one of the most frequent actions we users make…
Well god bless @Simoncbevans as he had the same thought 8 years ago I feel for you Simon !!!
PS, please feel free to add any posts you think deserve the title of “Forums Funniest Posts”
I though that CTR-c then CTR-v (on PC) or Cmd-c then Cmd-V (on Mac) would allow a copy, like nearly all other programs.
Ask Simon
Now, 8 years later, we have the stamp modifier for the Move Tool, which supplies exactly the functionality @simoncbevans was then trying to describe. Progress. Glacial
Still on SU2021 perpetual license here
Same here. I mostly use SU21 perpetual.
Did you try to hit the “Ctrl” key twice before moving an object to apply the stamp? 
There’s a stamp???
No, but well Simon and I were both lamenting the need to type two keys to execute a copy… considering that action is so common and dedicating one key would seem a good idea…
I can execute what you are doing but I still need two keystriokes to first initiate it, then one keystroke to continue…
If I recall correctly they initially (2021.0) proposed the persistent stamp as default copy behavior, but then (2021.1 maybe) they sorted this in this way.
I agree it’s a pretty common operation, but still the single copy (or array by input number) is even more common, at least for me.
So, all in all, I personally appreciated this double tap modifier more…