More than likely your team is aware but I wanted to let you know that while the load on the CPU spikes from the 30 % to the 80 % when I render cluster bombs, now the FPS only drops to the 27 FPS (being down to 2 or 0 and freezing before with no significant increase in CPU usage).
The ONLY difference is the CPU, so it is related to how the memory for these calculations is managed. Before I was using a Ryzen 3900X with multiple CCDs sharing cache that's away from the multiple chiplets. Now I am using a 5800X3d with a single 8 core CCD with access to the cache on top of the chiplet, so that significant reduction on latency to the L2 cache helps. The number of core reduction came with it, but the back and forth in data transfer was reduced as well as the IPC count.
einarabelc5's post in Cluster bomb detonation rendering - still drags system into a crawl was marked as the answer