Using sampled pxf analysis to simulate deterministic jitter

The Rapid Adoption Kit "Deterministic Jitter Measurement using SpectreRF" (https://support.cadence.com/apex/articleattachmentportal?id=a1O0V000009EVT2UAO) shows how a sampled pxf analysis can be used to simulate the deterministic jitter of a circuit due to power supply ripple. However, the setup shown there seems to be inspired by the recommended setup for a sampled pnoise analysis. In my opinion, a linear absolute frequency sweep up to the maximum ripple frequency with no additional sidebands will give a much clearer result here. Please compare the following plot to the plot on page 26 of the RAK:

For reference, here is the corresponding netlist:

// Design library name: WorkshopLib
// Design cell name: 4_inv_tb1
// Design view name: schematic
simulator lang=spectre
global 0
parameters ripple_freq=0 ripple_peak_volts=30m Clk_Frq=2.5G VDD=3.3
include "gpdk.scs" section=NN

// Library name: circuits
// Cell name: INV
// View name: schematic
subckt INV A Y gnd vdd
 NM2 (Y A gnd gnd) nmos1 w=(400n) l=180n as=440f ad=440f ps=2.8u \
 pd=2.8u m=(1)*(1)
 PM1 (Y A vdd vdd) pmos1 w=(600n) l=180n as=360f ad=180f ps=2.4u \
 pd=1.2u m=(1)*(2)
ends INV
// End of subcircuit definition.

// Library name: WorkshopLib
// Cell name: 4_inv_tb1
// View name: schematic
I3 (Int3 Out1 0 net01) INV
I2 (Int2 Int3 0 net01) INV
I1 (Int1 Int2 0 net01) INV
I0 (net10 Int1 0 net01) INV
V0 (net1 0) vsource dc=3.3 pacmag=1 type=dc
V1 (net10 0) vsource type=pulse val0=0 val1=3.3 period=1/Clk_Frq \
 rise=1/(40*Clk_Frq) fall=1/(40*Clk_Frq) width=19/(40*Clk_Frq) \
 fundname="In"
V4 (net01 net1) vsource type=sine freq=ripple_freq ampl=ripple_peak_volts \
 fundname="Ripple"
simulatorOptions options psfversion="1.4.0" reltol=1e-3 vabstol=1e-6 \
 iabstol=1e-12 temp=27 tnom=27 scalem=1.0 scale=1.0 gmin=1e-12 rforce=1 \
 maxnotes=5 maxwarns=5 digits=5 cols=80 pivrel=1e-3 \
 sensfile="../psf/sens.output" checklimitdest=psf 
pss pss fund=2.5G harms=1 autotstab=yes maxacfreq=100G
+ annotate=status
pxf ( Out1 0 Out1 0 ) pxf crossingdirection=rise
+ thresholdvalue=1.65 ptvtype=sampled start=0 stop=100G step=100M
+ maxsideband=0 annotate=status
saveOptions options save=allpub