It isn’t a case of the game being broken. The bandwidth of the ram is doubled when using dual channel and this is simply how it works. When the game needs something from memory it can be accessed so much faster with the ram in dual channel and this results in significantly less CPU load. The game is naturally heavy on the CPU because the CPUS job is to calculate player positions, handle all movements and physics, projectiles, etc. And it does this at the rate required to match the server, 60 times in a second (60hz servers). 64 players, 60 times per second all this information is being refreshed/updated.
In games that aren’t so cpu limited the bandwidth of the ram doesn’t really matter because the CPU isn’t maxing out anyways and while dual channel ram could reduce cpu load, it won’t actually improve the fps because the gpu is still the bottleneck.
Simply put, Dice cannot change this. This is the way memory works. They can improve the performance of single channel memory systems by optimizing CPU usage further but those changes will also help those using dual channel ram because this game is inevitably CPU bound in some scenarios how it is. However, these 40-50 fps boosts from going to dual channel are so significant that no optimization can eliminate it, upgrading is necessary.