I developed this license https://justdo.com/source-available-license , if someone wants to adopt it for their project, I'd love to provide its Latex form, just DM me. (With enough demand, I might Open Source the Source available license ;) )."
"The PolyForm Project is a group of experienced licensing lawyers and technologists developing simple, standardized, plain-language software source code licenses. PolyForm aims to fill gaps in the menu of standardized software licenses, like non-commercial, trial, and small-business-only terms."
The intent is that you should be able to make PRs, examine the source code, but not distribute Haystack for commercial reasons.
I believe the license should allow you make PRs and examine code (even in commercial settings), but I'll take a more in-depth look.
Thank you for raising this to my attention!
https://availability.kemitchell.com/