Two fully independent reverb engines, one per channel. There is no mono sum anywhere in the wet path and no mid/side stage, so channel separation is exact: feed silence to one input and that engine's output is bit-zero.
The engines use different delay-line tables and different early-reflection patterns, so left and right are genuinely different systems rather than scaled copies. Set them apart and the stereo image comes from the difference.
One control links them: Bass Coupling, which cross-mixes the two low bands to restore the low-frequency coherence a real room has. At zero the engines never meet.
Version 2.3.0