Copy pasting non-Steam game to reduce download time

This is about Ring of Elysium specifically. It came out many months ago on Garena. I have the latest update from before it came out of closed testing.

Now that it is on Steam, is there any way that I can copy the game files to the Steam directory so as to reduce download time? I tried just copy-pasting files, but Steam doesn't seem to recognize it.

Note that this method may not work for all games, and I have not tried it for this specific game, but it has been successful for me in the past.

1. Install the game through Steam
2. When it starts downloading, pause it and close the Steam client completely
3. Copy the files to folder Steam created, overwriting as necessary
4. Start steam

Now there could be a few situations:

• Steam does not recognize any of the files, and will continue to download the full game
• Steam does recognize some or all of the files, and might download only a few additional files

Either way, after it has finished, make sure to verify the integrity of the files by following the steps found at this link:

1. Restart your computer and launch Steam
2. From the Library section, right-click on the game and select Properties from the menu.
3. Select the Local files tab and click the Verify integrity of game files... button.
4. Steam will verify the game's files - this process may take several minutes.

Keep in mind that even though the game might look similar, there could be a lot of structural changes between a testing version and the release version, or even between a normal version and a Steam version. As such, this method might not work at all because there have been too many integral changes.