TBH I would not use a duplicate code detector at all. That would solve the problem. I tend to find excessive deduplication to be a bigger problem then have some unnecessary duplication.
If you need a tool to find duplicate code you are probably down the route of excess. They only really time you need to deduplicate code is when it causes a problem for maintenance. Then it is typically trivially easy to find it without a special tool.
The time to beat a game is generally for the main story if you don't take ages doing other things. Quite often with side quests or other non essential steps like collecting things or trying to 100% a game it will take way longer then the estimated time to complete. This is epically true for more open-world type of games with lots of places to explore.