Common impact LPA add-ons that tend to work:

- Define the **impact thesis** clearly in the mandate, but keep room for judgment
- Add **negative screens / prohibited sectors**
- Require **annual impact reporting** with a small set of measurable KPIs
- Use **LPAC oversight** for conflicts or impact-policy exceptions
- Put bespoke rights in **side letters**, not the core LPA

Usually avoid:

- **Hard impact carry** or carry forfeiture tied to subjective metrics unless metrics, verifier, timing, and dispute process are extremely clear
- Broad LP vetoes over ordinary investment decisions
- Overly detailed KPI covenants that create reporting drag and hurt execution

Rule of thumb:
- Put principles in the LPA
- Put operating detail in policy documents / side letters
- Keep the fund investable first, reportable second

References:
- https://decilegroup.com/articles/lpa-template-for-vc-funds
- https://decilehub.com/base/1-general_questions/163975-cornerstone-lpa-what-protections-can-an-lpa-offer-to-risk-averse-lps-without-limiting-the-gp-s-ability-to-make-timely-investment-decisions-or-manage-the-portfolio-effectively