Something that's actually helped me get a better handle on my PEK has been using it to recreate patches on my Sub 37 and on my JP-08. I realize that seems silly - but the Poly Evolver invites you to make bugfuck weird sounds, and has such a wide range on each attribute, that sometimes I get lost in random design, enjoying the catharsis that comes with building out those strange sounds, and I end up with something that no one else would ever want to hear.
So when I make a lush pad on my JP08, I see if I can recreate it on the PEK. It helps me get my gain staging under control, it reminds me to be judicious with the filter. I had a gnarly bass patch on my Sub 37, and found that with a little more restraint than I often use, I was able to make an even chonkier variation of that patch on the PEK.
Once I have that strong baseline, I can then go beyond that and bring in some of the more unique elements this synth can offer.
I basically took this technique from my experience with the Tempest. I found the original presets disappointing, but I also wasn't super thrilled with my own attempts at creating synth percussion. When the Roland TR-8 came out, I found myself eyeing it up, because I had let my Tempest collect dust for a year or two, having been frustrated with the sounds I was ekeing out of it. Did I really need to drop hundreds of dollars on another drum machine? I had the ultimate percussion synthesizer, I just hadn't been using it right. Ironically, I took a cue from Roland's promo videos for the AIRA line, where they showed engineers analyzing sound in free oscilloscope software called Visual Analyzer.
I downloaded VA, plugged in my TR-606, opened the Sound on Sound Synth Secrets articles about making 808 drums, and spent a long time building out Roland percussion, and now not only had my fever subsided for the TR-8, but I sold off my TR-606 and DR-110, and had a great starting point for developing my own custom drums, and I really, really got to know the Tempest during that process.