You still don't want to save a copy in the same folder. Here's what's going to happen ...
Scenario 1:
You copy an RTP file into the same folder, make changes to it.
Use it in your game, with the new name.
Compress your game without RTP to keep its size down.
Send it to friends.
Friends can't play game because, although they've installed the RTP, you've ADDED TO the RTP and didn't give them the extra files.
Scenario 2:
You copy an RTP file into the same folder, make changes to it.
Use it in your game, with the new name.
Compress your game WITH RTP, even though it's going to give you a bigger file size, because you've added to the RTP.
Send it to friends.
Friends play game.
You make a new game, do the same thing.
Compress your game WITH RTP, it's going to be even BIGGER than before, because now it's got the ORIGINAL RTP, the new files you created for THIS game, AND the files you created for the LAST game but aren't using.
Every game gets bigger and bigger because you've said, each time "this image, that I'm only using in THIS game, is going to go into the RTP, which is used by ALL games".
The idea is to leave the RTP as-is, and if you want to copy or change anything, use the Resource Manager to put it into the folder for that specific project. Then you compress WITHOUT the RTP if you want to keep the file size down, and your custom sprites will still be included.
