Honestly, you should charge actual money for this.
Not a bad idea at all, plus the templates you already have are pretty neat. I could see applications w.r.t. professional development or even marketing to product people with the purpose of simplifying product roadmaps (and sharing with C-levels, etc.).
You have something here, screw donations. Free users suck anyway; my free project[1] has ~1500 MAU and I kind of want to stop working on it because the entitlement is unreal.