I know the feeling. The precursor to PL was a hideously complex spreadsheet of my own. You're probably a better spreadsheet wrangler than me, b/c in my case all the formulas eventually got so out-of-hand that it became cumbersome for me to maintain and really trust that thing.

When I was initially casting about for alternate tools that might be a step up from that spreadsheet, I found myself frustrated when I ran into anything opaque or where methodology / assumptions weren't clear. With PL, I've made an effort to expose as many of those as I can directly to the user (while packaged into a UI that tries not to overwhelm), but I'm sure at the end of the day it's always going to be a reflection of the parameters and decision space I had in mind when designing it.

If you ever check it out and run into areas where you feel the model needs more clarity, definitely let me know.