How can the receiver in the 112G PAM4 ADC-Based SerDes Model support two stages of FFE—one with fixed taps (RxFFE) and one with floating taps (RxFloatFFE)

Architectural 112G PAM4 ADC-Based SerDes Model - MATLAB & Simulink

After studying the case "Architectural 112G PAM4 ADC-Based SerDes Model" provided by MathWorks, I hope to make some modifications according to my customized needs. The ADC subsystem is composed of custom ADC, Demux, RxFFE(Fixed 21 taps), DFE, Phase Detector, Loop Filter, and VCO System object™ blocks. I want to add a stage of floating tap FFE(floating 48 taps + fixed 17 taps + floating 48 taps), named RxFloatFFE, changing from Figure 1 to Figure 2. When I add the TapWeights corresponding to RxFloatFFE under the ADC_EQ module in the SerDes IBIS-AMI Manager's AMI-RX, I found that the icon is grayed out (as shown in Figure 3), and MathWorks does not allow adding TapWeights for RxFloatFFE. How should this be resolved?

I hope that the TapWeights for both RxFFE and RxFloatFFE can be calculated from the Init Pulse response.