I have produced first-order plots of the magnitude and phase strain uncertainty.
These plots look very good mostly because I am using only statistical uncertainty, and in some cases eyeballing the systematics from residual plots to get an idea of our final uncertainty.
These are the values of sigma I used for the various parameters important to strain:

σ_|A_tst| = 0.01*abs(A_tst);    1% uncertainty
σ_|A_pu| = 0.039*abs(A_pu);     3% uncertainty
σ_|C_r| = 0.01*abs(C_r);        1% uncertainty
σ_|kappa_tst| =  0.0040;        std of first order |kappa_tst| calculations
σ_|kappa_pu| = 0.0066;          std of first order |kappa_pu| calculations
σ_φ_A_tst = 5;                  5 degree assumption
σ_φ_A_pu = 5;                   5 degree assumption
σ_φ_C_r = 5;                    5 degree assumption
σ_φ_kappa_tst = 0.27;           std of first order phi_kappa_tst calculations
σ_φ_kappa_pu = 0.35;            std of first order phi_kappa_tst calculations
σ_kappa_C = 0.0049;             std of first order kappa_C calcs
σ_f_c = 23.4731;                std of first order f_c calcs

Plots 1 and 2 are the Magnitude and Phase Uncertainty Plots using the Response function.  Recall the Response function R = (1 + G) / C.  I will also have the "Two Signal" calibration uncertainty (h = DARM_ERR / C + A * DARM_CTRL), and I expect them to coincide nicely someday soon.
Note that the max uncertainty in magnitude is ~4% at 30 Hz and the max uncertainty in phase is ~7 degrees.  (Remember that these are first order plots, but this is surely auspicious!)

Plots 3 and 4 are the squared component plots where we can see which parts of the uncertainty dominate where.
For magnitude, phi_A_pu and phi_A_tst dominate at low frequency and phi_C_r dominates at high frequency.
For phase, phi_A_pu dominates at low frequency and phi_C_r dominates at high frequency.

Next I will ensure the Two Signal and Response Function uncertainties are similar, then I will begin to inform our sigmas more intelligently.