A: cic_decimator_4x_enhanced.v reset_h max_fanout 50→25. More replicas
mean each drives fewer DSP48 RSTB loads, letting Vivado place each
closer to its consumers. Targets the rep__24 → comb_reg[4]/RSTB path
that failed clk_mmcm_out0 intra by -10 ps (1.4 ns of pure routing).
B: adc_clk_mmcm.xdc BUFIO↔BUFG max_delay 2.500→2.700 ns. The 2.5 ns
target was tighter than achievable for the IDDR (ILOGIC) → FDRE (fabric
SLICE) re-registration. The effective window is the BUFIO↔BUFG phase
relationship (not the clock period), so 2.7 ns remains safe. Fixes the
adc_dco_p→clk_mmcm_out0 inter path -113 ps failure on lane 7.