I personally did a form of partigyle brew but did not set up a profile for it.
What I did was assume 75% usage [meaning I counted my grains for the second batch as 25%, by weight, compared to the first brew. I found this to be a bit too high, it's probably more like 1/8 (12.5%) but have not had the chance to attempt again yet.
I also plan on doing a partigyle where I brew initial beer and for the second run I add in 1-2# base malts and use pH stabilizer to get me in range for conversion. You can also choose to add some amylase enzyme too.
When/if I ever get this done I'll post here or in a new thread.