In general they just increase the numbers on everything when they go up a generation.
e.g. if you check in 4 directions to see if you can reuse a chunk then make it check in 8 or 16.
Faster encoders will have smart heuristics on when to use these new abilities and when to skip them but the reference encoder will try everything in a dumb way to eke out a tiny win to maximize a theoretical advantage and map out the extreme best case.
In general they just increase the numbers on everything when they go up a generation.
e.g. if you check in 4 directions to see if you can reuse a chunk then make it check in 8 or 16.
Faster encoders will have smart heuristics on when to use these new abilities and when to skip them but the reference encoder will try everything in a dumb way to eke out a tiny win to maximize a theoretical advantage and map out the extreme best case.