I have conducted a study on how to use the .bode command and included a simple comparison of .meas FRA in the last section.
Qspice/Guideline/Qspice - Bode Frequency Response Analysis (.bode).pdf at main · KSKelvin-Github/Qspice
Professor Marcos Alonso (@marcos.uniovi) has a YouTube channel with tutorials on frequency response in SMPS using Qspice. (look for Qspice#4 and Qspice#5)
Marcos Alonso - YouTube
@physicboy has his own project of FRA analyzer
4-Channel FRA analyzer - QSPICE - Qorvo Tech Forum