OptionalseqSequential head: "markov" (Eq 5, default) or "rnn" (Eq 6).
OptionalstsSTS calibration (§3.2.1); absent = no confidence pruning.
Target layer indices tapped for H_ctx (Eq 2). nLayers-of-target..sentinel. For e4b (42 layers): index 0..41 = post-layer residual, 42 = post-finalNorm.
Backbone depth (paper default 5).